Exemple #1
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    def filtered_labels(self, workspace, gridding):
        '''Filter labels by proximity to edges of grid'''
        #
        # A label might slightly graze a grid other than its own or
        # a label might be something small in a corner of the grid.
        # This function filters out those parts of the guide labels matrix
        #
        assert isinstance(gridding, cpg.CPGridInfo)
        guide_labels = self.get_guide_labels(workspace)
        labels = self.fill_grid(workspace, gridding)

        centers = np.zeros((2, np.max(guide_labels) + 1))
        centers[:, 1:] = centers_of_labels(guide_labels)
        bad_centers = ((~np.isfinite(centers[0, :])) |
                       (~np.isfinite(centers[1, :])) |
                       (centers[0, :] >= labels.shape[0]) |
                       (centers[1, :] >= labels.shape[1]))
        centers = np.round(centers).astype(int)
        masked_labels = labels.copy()
        x_border = int(np.ceil(gridding.x_spacing / 10))
        y_border = int(np.ceil(gridding.y_spacing / 10))
        #
        # erase anything that's not like what's next to it
        #
        ymask = labels[y_border:, :] != labels[:-y_border, :]
        masked_labels[y_border:, :][ymask] = 0
        masked_labels[:-y_border, :][ymask] = 0
        xmask = labels[:, x_border:] != labels[:, :-x_border]
        masked_labels[:, x_border:][xmask] = 0
        masked_labels[:, :-x_border][xmask] = 0
        #
        # Find out the grid that each center falls into. If a center falls
        # into the border region, it will get a grid number of 0 and be
        # erased. The guide objects may fall below or to the right of the
        # grid or there may be gaps in numbering, so we set the center label
        # of bad centers to 0.
        #
        centers[:, bad_centers] = 0
        lcenters = masked_labels[centers[0, :], centers[1, :]]
        lcenters[bad_centers] = 0
        #
        # Use the guide labels to look up the corresponding center for
        # each guide object pixel. Mask out guide labels that don't match
        # centers.
        #
        mask = np.zeros(guide_labels.shape, bool)
        ii_labels = np.index_exp[0:labels.shape[0], 0:labels.shape[1]]
        mask[ii_labels] = lcenters[guide_labels[ii_labels]] != labels
        mask[guide_labels == 0] = True
        mask[lcenters[guide_labels] == 0] = True
        filtered_guide_labels = guide_labels.copy()
        filtered_guide_labels[mask] = 0
        return filtered_guide_labels
Exemple #2
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    def filtered_labels(self, workspace, gridding):
        '''Filter labels by proximity to edges of grid'''
        #
        # A label might slightly graze a grid other than its own or
        # a label might be something small in a corner of the grid.
        # This function filters out those parts of the guide labels matrix
        #
        assert isinstance(gridding, cpg.CPGridInfo)
        guide_labels = self.get_guide_labels(workspace)
        labels = self.fill_grid(workspace,gridding)

        centers = np.zeros((2,np.max(guide_labels)+1))
        centers[:,1:] = centers_of_labels(guide_labels)
        bad_centers = ((~ np.isfinite(centers[0,:])) |
                       (~ np.isfinite(centers[1,:])) |
                       (centers[0,:] >= labels.shape[0]) |
                       (centers[1,:] >= labels.shape[1]))
        centers = np.round(centers).astype(int)
        masked_labels = labels.copy()
        x_border = int(np.ceil(gridding.x_spacing /10))
        y_border = int(np.ceil(gridding.y_spacing / 10))
        #
        # erase anything that's not like what's next to it
        #
        ymask = labels[y_border:,:] != labels[:-y_border,:]
        masked_labels[y_border:,:][ymask] = 0
        masked_labels[:-y_border,:][ymask] = 0
        xmask = labels[:,x_border:] != labels[:,:-x_border]
        masked_labels[:,x_border:][xmask] = 0
        masked_labels[:,:-x_border][xmask] = 0
        #
        # Find out the grid that each center falls into. If a center falls
        # into the border region, it will get a grid number of 0 and be
        # erased. The guide objects may fall below or to the right of the
        # grid or there may be gaps in numbering, so we set the center label
        # of bad centers to 0.
        #
        centers[:,bad_centers] = 0
        lcenters = masked_labels[centers[0,:],centers[1,:]]
        lcenters[bad_centers] = 0
        #
        # Use the guide labels to look up the corresponding center for
        # each guide object pixel. Mask out guide labels that don't match
        # centers.
        #
        mask = np.zeros(guide_labels.shape, bool)
        ii_labels = np.index_exp[0:labels.shape[0],0:labels.shape[1]]
        mask[ii_labels] = lcenters[guide_labels[ii_labels]] != labels
        mask[guide_labels == 0] = True
        mask[lcenters[guide_labels] == 0] = True
        filtered_guide_labels = guide_labels.copy()
        filtered_guide_labels[mask] = 0
        return filtered_guide_labels
 def calculate_centroid_distances(self, workspace, parent_name):
     '''Calculate the centroid-centroid distance between parent & child'''
     meas = workspace.measurements
     assert isinstance(meas,cpmeas.Measurements)
     sub_object_name = self.sub_object_name.value
     parents = workspace.object_set.get_objects(parent_name)
     children = workspace.object_set.get_objects(sub_object_name)
     parents_of = self.get_parents_of(workspace, parent_name)
     pcenters = centers_of_labels(parents.segmented).transpose()
     ccenters = centers_of_labels(children.segmented).transpose()
     if pcenters.shape[0] == 0 or ccenters.shape[0] == 0:
         dist = np.array([np.NaN] * len(parents_of))
     else:
         #
         # Make indexing of parents_of be same as pcenters
         #
         parents_of = parents_of - 1
         mask = (parents_of != -1) | (parents_of > pcenters.shape[0])
         dist = np.array([np.NaN] * ccenters.shape[0])
         dist[mask] = np.sqrt(np.sum((ccenters[mask,:] - 
                                      pcenters[parents_of[mask],:])**2,1))
     meas.add_measurement(sub_object_name, FF_CENTROID % parent_name, dist)
Exemple #4
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 def calculate_centroid_distances(self, workspace, parent_name):
     '''Calculate the centroid-centroid distance between parent & child'''
     meas = workspace.measurements
     assert isinstance(meas, cpmeas.Measurements)
     sub_object_name = self.sub_object_name.value
     parents = workspace.object_set.get_objects(parent_name)
     children = workspace.object_set.get_objects(sub_object_name)
     parents_of = self.get_parents_of(workspace, parent_name)
     pcenters = centers_of_labels(parents.segmented).transpose()
     ccenters = centers_of_labels(children.segmented).transpose()
     if pcenters.shape[0] == 0 or ccenters.shape[0] == 0:
         dist = np.array([np.NaN] * len(parents_of))
     else:
         #
         # Make indexing of parents_of be same as pcenters
         #
         parents_of = parents_of - 1
         mask = (parents_of != -1) | (parents_of > pcenters.shape[0])
         dist = np.array([np.NaN] * ccenters.shape[0])
         dist[mask] = np.sqrt(
             np.sum((ccenters[mask, :] - pcenters[parents_of[mask], :])**2,
                    1))
     meas.add_measurement(sub_object_name, FF_CENTROID % parent_name, dist)
Exemple #5
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    def run_automatic(self, workspace):
        """Automatically define a grid based on objects

        Returns a CPGridInfo object
        """
        objects = workspace.object_set.get_objects(self.object_name.value)
        centroids = centers_of_labels(objects.segmented)
        try:
            if centroids.shape[1] < 2:
                #
                # Failed if too few objects
                #
                raise RuntimeError("%s has too few grid cells" % self.object_name.value)
            #
            # Artificially swap these to match the user's orientation
            #
            first_row, second_row = (1, self.grid_rows.value)
            if self.origin in (NUM_BOTTOM_LEFT, NUM_BOTTOM_RIGHT):
                first_row, second_row = (second_row, first_row)
            first_column, second_column = (1, self.grid_columns.value)
            if self.origin in (NUM_TOP_RIGHT, NUM_BOTTOM_RIGHT):
                first_column, second_column = (second_column, first_column)
            first_x = np.min(centroids[1, :])
            first_y = np.min(centroids[0, :])
            second_x = np.max(centroids[1, :])
            second_y = np.max(centroids[0, :])
            result = self.build_grid_info(
                first_x,
                first_y,
                first_row,
                first_column,
                second_x,
                second_y,
                second_row,
                second_column,
                objects.segmented.shape,
            )
        except Exception:
            if self.failed_grid_choice != FAIL_NO:
                result = self.get_good_gridding(workspace)
                if result is None:
                    raise RuntimeError(
                        "%s has too few grid cells and there is no previous successful grid" % self.object_name.value
                    )
            raise
        return result
Exemple #6
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 def run_natural_circle(self, workspace, gridding):
     '''Return a labels matrix composed of circles found from objects'''
     #
     # Find the centroid of any guide label in a grid
     #
     guide_label = self.filtered_labels(workspace, gridding)
     labels = self.fill_grid(workspace,gridding)
     labels[guide_label[0:labels.shape[0],0:labels.shape[1]] == 0] = 0
     centers_i, centers_j = centers_of_labels(labels)
     nmissing = np.max(gridding.spot_table) - len(centers_i)
     if nmissing > 0:
         centers_i = np.hstack((centers_i, [np.NaN] * nmissing))
         centers_j = np.hstack((centers_j, [np.NaN] * nmissing))
     #
     # Broadcast these using the spot table
     #
     centers_i = centers_i[gridding.spot_table-1]
     centers_j = centers_j[gridding.spot_table-1]
     return self.run_circle(workspace, gridding, centers_i, centers_j)
Exemple #7
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 def run_natural_circle(self, workspace, gridding):
     '''Return a labels matrix composed of circles found from objects'''
     #
     # Find the centroid of any guide label in a grid
     #
     guide_label = self.filtered_labels(workspace, gridding)
     labels = self.fill_grid(workspace, gridding)
     labels[guide_label[0:labels.shape[0], 0:labels.shape[1]] == 0] = 0
     centers_i, centers_j = centers_of_labels(labels)
     nmissing = np.max(gridding.spot_table) - len(centers_i)
     if nmissing > 0:
         centers_i = np.hstack((centers_i, [np.NaN] * nmissing))
         centers_j = np.hstack((centers_j, [np.NaN] * nmissing))
     #
     # Broadcast these using the spot table
     #
     centers_i = centers_i[gridding.spot_table - 1]
     centers_j = centers_j[gridding.spot_table - 1]
     return self.run_circle(workspace, gridding, centers_i, centers_j)
    def make_workspace(self, measurement, labels=None, image=None):
        object_set = cpo.ObjectSet()
        module = D.DisplayDataOnImage()
        module.module_num = 1
        module.image_name.value = INPUT_IMAGE_NAME
        module.display_image.value = OUTPUT_IMAGE_NAME
        module.objects_name.value = OBJECTS_NAME
        m = cpmeas.Measurements()

        if labels is None:
            module.objects_or_image.value = D.OI_IMAGE
            m.add_image_measurement(MEASUREMENT_NAME, measurement)
            if image is None:
                image = np.zeros((50, 120))
        else:
            module.objects_or_image.value = D.OI_OBJECTS
            o = cpo.Objects()
            o.segmented = labels
            object_set.add_objects(o, OBJECTS_NAME)
            m.add_measurement(OBJECTS_NAME, MEASUREMENT_NAME,
                              np.array(measurement))
            y, x = centers_of_labels(labels)
            m.add_measurement(OBJECTS_NAME, "Location_Center_X", x)
            m.add_measurement(OBJECTS_NAME, "Location_Center_Y", y)
            if image is None:
                image = np.zeros(labels.shape)
        module.measurement.value = MEASUREMENT_NAME

        pipeline = cpp.Pipeline()

        def callback(caller, event):
            self.assertFalse(isinstance(event, cpp.RunExceptionEvent))

        pipeline.add_listener(callback)
        pipeline.add_module(module)
        image_set_list = cpi.ImageSetList()
        image_set = image_set_list.get_image_set(0)
        image_set.add(INPUT_IMAGE_NAME, cpi.Image(image))

        workspace = cpw.Workspace(pipeline, module, image_set, object_set, m,
                                  image_set_list)
        return workspace, module
Exemple #9
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    def run_automatic(self, workspace):
        '''Automatically define a grid based on objects

        Returns a CPGridInfo object
        '''
        objects = workspace.object_set.get_objects(self.object_name.value)
        centroids = centers_of_labels(objects.segmented)
        try:
            if centroids.shape[1] < 2:
                #
                # Failed if too few objects
                #
                raise RuntimeError("%s has too few grid cells" %
                                   self.object_name.value)
            #
            # Artificially swap these to match the user's orientation
            #
            first_row, second_row = (1, self.grid_rows.value)
            if self.origin in (NUM_BOTTOM_LEFT, NUM_BOTTOM_RIGHT):
                first_row, second_row = (second_row, first_row)
            first_column, second_column = (1, self.grid_columns.value)
            if self.origin in (NUM_TOP_RIGHT, NUM_BOTTOM_RIGHT):
                first_column, second_column = (second_column, first_column)
            first_x = np.min(centroids[1, :])
            first_y = np.min(centroids[0, :])
            second_x = np.max(centroids[1, :])
            second_y = np.max(centroids[0, :])
            result = self.build_grid_info(first_x, first_y, first_row,
                                          first_column, second_x, second_y,
                                          second_row, second_column,
                                          objects.segmented.shape)
        except Exception:
            if self.failed_grid_choice != FAIL_NO:
                result = self.get_good_gridding(workspace)
                if result is None:
                    raise RuntimeError(
                        "%s has too few grid cells and there is no previous successful grid"
                        % self.object_name.value)
            raise
        return result
 def make_workspace(self, measurement, labels = None, image = None):
     object_set = cpo.ObjectSet()
     module = D.DisplayDataOnImage()
     module.module_num = 1
     module.image_name.value = INPUT_IMAGE_NAME
     module.display_image.value = OUTPUT_IMAGE_NAME
     module.objects_name.value = OBJECTS_NAME
     m = cpmeas.Measurements()
     
     if labels is None:
         module.objects_or_image.value = D.OI_IMAGE
         m.add_image_measurement(MEASUREMENT_NAME, measurement)
         if image is None:
             image = np.zeros((50,120))
     else:
         module.objects_or_image.value = D.OI_OBJECTS
         o = cpo.Objects()
         o.segmented = labels
         object_set.add_objects(o, OBJECTS_NAME)
         m.add_measurement(OBJECTS_NAME, MEASUREMENT_NAME, np.array(measurement))
         y,x = centers_of_labels(labels)
         m.add_measurement(OBJECTS_NAME, "Location_Center_X",x)
         m.add_measurement(OBJECTS_NAME, "Location_Center_Y",y)
         if image is None:
             image = np.zeros(labels.shape)
     module.measurement.value = MEASUREMENT_NAME
     
     pipeline = cpp.Pipeline()
     def callback(caller, event):
         self.assertFalse(isinstance(event, cpp.RunExceptionEvent))
     
     pipeline.add_listener(callback)
     pipeline.add_module(module)
     image_set_list = cpi.ImageSetList()
     image_set = image_set_list.get_image_set(0)
     image_set.add(INPUT_IMAGE_NAME,cpi.Image(image))
     
     workspace = cpw.Workspace(pipeline, module, image_set, object_set,
                               m, image_set_list)
     return workspace, module
 def do_measurements(self, workspace, image_name, object_name, 
                     center_object_name, center_choice,
                     bin_count_settings, dd):
     '''Perform the radial measurements on the image set
     
     workspace - workspace that holds images / objects
     image_name - make measurements on this image
     object_name - make measurements on these objects
     center_object_name - use the centers of these related objects as
                   the centers for radial measurements. None to use the
                   objects themselves.
     center_choice - the user's center choice for this object:
                   C_SELF, C_CENTERS_OF_OBJECTS or C_EDGES_OF_OBJECTS.
     bin_count_settings - the bin count settings group
     d - a dictionary for saving reusable partial results
     
     returns one statistics tuple per ring.
     '''
     assert isinstance(workspace, cpw.Workspace)
     assert isinstance(workspace.object_set, cpo.ObjectSet)
     bin_count = bin_count_settings.bin_count.value
     wants_scaled = bin_count_settings.wants_scaled.value
     maximum_radius = bin_count_settings.maximum_radius.value
     
     image = workspace.image_set.get_image(image_name,
                                           must_be_grayscale=True)
     objects = workspace.object_set.get_objects(object_name)
     labels, pixel_data = cpo.crop_labels_and_image(objects.segmented,
                                                    image.pixel_data)
     nobjects = np.max(objects.segmented)
     measurements = workspace.measurements
     assert isinstance(measurements, cpmeas.Measurements)
     if nobjects == 0:
         for bin in range(1, bin_count+1):
             for feature in (F_FRAC_AT_D, F_MEAN_FRAC, F_RADIAL_CV):
                 feature_name = (
                     (feature + FF_GENERIC) % (image_name, bin, bin_count))
                 measurements.add_measurement(
                     object_name, "_".join([M_CATEGORY, feature_name]),
                     np.zeros(0))
                 if not wants_scaled:
                     measurement_name = "_".join([M_CATEGORY, feature,
                                                  image_name, FF_OVERFLOW])
                     measurements.add_measurement(
                         object_name, measurement_name, np.zeros(0))
         return [(image_name, object_name, "no objects","-","-","-","-")]
     name = (object_name if center_object_name is None 
             else "%s_%s"%(object_name, center_object_name))
     if dd.has_key(name):
         normalized_distance, i_center, j_center, good_mask = dd[name]
     else:
         d_to_edge = distance_to_edge(labels)
         if center_object_name is not None:
             #
             # Use the center of the centering objects to assign a center
             # to each labeled pixel using propagation
             #
             center_objects=workspace.object_set.get_objects(center_object_name)
             center_labels, cmask = cpo.size_similarly(
                 labels, center_objects.segmented)
             pixel_counts = fix(scind.sum(
                 np.ones(center_labels.shape),
                 center_labels,
                 np.arange(1, np.max(center_labels)+1,dtype=np.int32)))
             good = pixel_counts > 0
             i,j = (centers_of_labels(center_labels) + .5).astype(int)
             if center_choice == C_CENTERS_OF_OTHER:
                 #
                 # Reduce the propagation labels to the centers of
                 # the centering objects
                 #
                 ig = i[good]
                 jg = j[good]
                 lg = np.arange(1, len(i)+1)[good]
                 center_labels = np.zeros(center_labels.shape, int)
                 center_labels[ig,jg] = lg
             cl,d_from_center = propagate(np.zeros(center_labels.shape),
                                          center_labels,
                                          labels != 0, 1)
             #
             # Erase the centers that fall outside of labels
             #
             cl[labels == 0] = 0
             #
             # If objects are hollow or crescent-shaped, there may be
             # objects without center labels. As a backup, find the
             # center that is the closest to the center of mass.
             #
             missing_mask = (labels != 0) & (cl == 0)
             missing_labels = np.unique(labels[missing_mask])
             if len(missing_labels):
                 all_centers = centers_of_labels(labels)
                 missing_i_centers, missing_j_centers = \
                                  all_centers[:, missing_labels-1]
                 di = missing_i_centers[:, np.newaxis] - ig[np.newaxis, :]
                 dj = missing_j_centers[:, np.newaxis] - jg[np.newaxis, :]
                 missing_best = lg[np.lexsort((di*di + dj*dj, ))[:, 0]]
                 best = np.zeros(np.max(labels) + 1, int)
                 best[missing_labels] = missing_best
                 cl[missing_mask] = best[labels[missing_mask]]
                 #
                 # Now compute the crow-flies distance to the centers
                 # of these pixels from whatever center was assigned to
                 # the object.
                 #
                 iii, jjj = np.mgrid[0:labels.shape[0], 0:labels.shape[1]]
                 di = iii[missing_mask] - i[cl[missing_mask] - 1]
                 dj = jjj[missing_mask] - j[cl[missing_mask] - 1]
                 d_from_center[missing_mask] = np.sqrt(di*di + dj*dj)
         else:
             # Find the point in each object farthest away from the edge.
             # This does better than the centroid:
             # * The center is within the object
             # * The center tends to be an interesting point, like the
             #   center of the nucleus or the center of one or the other
             #   of two touching cells.
             #
             i,j = maximum_position_of_labels(d_to_edge, labels, objects.indices)
             center_labels = np.zeros(labels.shape, int)
             center_labels[i,j] = labels[i,j]
             #
             # Use the coloring trick here to process touching objects
             # in separate operations
             #
             colors = color_labels(labels)
             ncolors = np.max(colors)
             d_from_center = np.zeros(labels.shape)
             cl = np.zeros(labels.shape, int)
             for color in range(1,ncolors+1):
                 mask = colors == color
                 l,d = propagate(np.zeros(center_labels.shape),
                                 center_labels,
                                 mask, 1)
                 d_from_center[mask] = d[mask]
                 cl[mask] = l[mask]
         good_mask = cl > 0
         if center_choice == C_EDGES_OF_OTHER:
             # Exclude pixels within the centering objects
             # when performing calculations from the centers
             good_mask = good_mask & (center_labels == 0)
         i_center = np.zeros(cl.shape)
         i_center[good_mask] = i[cl[good_mask]-1]
         j_center = np.zeros(cl.shape)
         j_center[good_mask] = j[cl[good_mask]-1]
         
         normalized_distance = np.zeros(labels.shape)
         if wants_scaled:
             total_distance = d_from_center + d_to_edge
             normalized_distance[good_mask] = (d_from_center[good_mask] /
                                               (total_distance[good_mask] + .001))
         else:
             normalized_distance[good_mask] = \
                 d_from_center[good_mask] / maximum_radius
         dd[name] = [normalized_distance, i_center, j_center, good_mask]
     ngood_pixels = np.sum(good_mask)
     good_labels = labels[good_mask]
     bin_indexes = (normalized_distance * bin_count).astype(int)
     bin_indexes[bin_indexes > bin_count] = bin_count
     labels_and_bins = (good_labels-1,bin_indexes[good_mask])
     histogram = coo_matrix((pixel_data[good_mask], labels_and_bins),
                            (nobjects, bin_count+1)).toarray()
     sum_by_object = np.sum(histogram, 1)
     sum_by_object_per_bin = np.dstack([sum_by_object]*(bin_count + 1))[0]
     fraction_at_distance = histogram / sum_by_object_per_bin
     number_at_distance = coo_matrix((np.ones(ngood_pixels),labels_and_bins),
                                     (nobjects, bin_count+1)).toarray()
     object_mask = number_at_distance > 0
     sum_by_object = np.sum(number_at_distance, 1)
     sum_by_object_per_bin = np.dstack([sum_by_object]*(bin_count+1))[0]
     fraction_at_bin = number_at_distance / sum_by_object_per_bin
     mean_pixel_fraction = fraction_at_distance / (fraction_at_bin +
                                                   np.finfo(float).eps)
     masked_fraction_at_distance = masked_array(fraction_at_distance,
                                                ~object_mask)
     masked_mean_pixel_fraction = masked_array(mean_pixel_fraction,
                                               ~object_mask)
     # Anisotropy calculation.  Split each cell into eight wedges, then
     # compute coefficient of variation of the wedges' mean intensities
     # in each ring.
     #
     # Compute each pixel's delta from the center object's centroid
     i,j = np.mgrid[0:labels.shape[0], 0:labels.shape[1]]
     imask = i[good_mask] > i_center[good_mask]
     jmask = j[good_mask] > j_center[good_mask]
     absmask = (abs(i[good_mask] - i_center[good_mask]) > 
                abs(j[good_mask] - j_center[good_mask]))
     radial_index = (imask.astype(int) + jmask.astype(int)*2 + 
                     absmask.astype(int)*4)
     statistics = []
     for bin in range(bin_count + (0 if wants_scaled else 1)):
         bin_mask = (good_mask & (bin_indexes == bin))
         bin_pixels = np.sum(bin_mask)
         bin_labels = labels[bin_mask]
         bin_radial_index = radial_index[bin_indexes[good_mask] == bin]
         labels_and_radii = (bin_labels-1, bin_radial_index)
         radial_values = coo_matrix((pixel_data[bin_mask],
                                     labels_and_radii),
                                    (nobjects, 8)).toarray()
         pixel_count = coo_matrix((np.ones(bin_pixels), labels_and_radii),
                                  (nobjects, 8)).toarray()
         mask = pixel_count==0
         radial_means = masked_array(radial_values / pixel_count, mask)
         radial_cv = np.std(radial_means,1) / np.mean(radial_means, 1)
         radial_cv[np.sum(~mask,1)==0] = 0
         for measurement, feature, overflow_feature in (
             (fraction_at_distance[:,bin], MF_FRAC_AT_D, OF_FRAC_AT_D),
             (mean_pixel_fraction[:,bin], MF_MEAN_FRAC, OF_MEAN_FRAC),
             (np.array(radial_cv), MF_RADIAL_CV, OF_RADIAL_CV)):
             
             if bin == bin_count:
                 measurement_name = overflow_feature % image_name
             else:
                 measurement_name = feature % (image_name, bin+1, bin_count)
             measurements.add_measurement(object_name,
                                          measurement_name,
                                          measurement)
         radial_cv.mask = np.sum(~mask,1)==0
         bin_name = str(bin+1) if bin < bin_count else "Overflow"
         statistics += [(image_name, object_name, bin_name, str(bin_count),
                         round(np.mean(masked_fraction_at_distance[:,bin]),4),
                         round(np.mean(masked_mean_pixel_fraction[:, bin]),4),
                         round(np.mean(radial_cv),4))]
     return statistics
 def filter_using_image(self, workspace, mask):
     '''Filter out connections using local intensity minima between objects
     
     workspace - the workspace for the image set
     mask - mask of background points within the minimum distance
     '''
     #
     # NOTE: This is an efficient implementation and an improvement
     #       in accuracy over the Matlab version. It would be faster and
     #       more accurate to eliminate the line-connecting and instead
     #       do the following:
     #     * Distance transform to get the coordinates of the closest
     #       point in an object for points in the background that are
     #       at most 1/2 of the max distance between objects.
     #     * Take the intensity at this closest point and similarly
     #       label the background point if the background intensity
     #       is at least the minimum intensity fraction
     #     * Assume there is a connection between objects if, after this
     #       labeling, there are adjacent points in each object.
     #
     # As it is, the algorithm duplicates the Matlab version but suffers
     # for cells whose intensity isn't high in the centroid and clearly
     # suffers when two cells touch at some point that's off of the line
     # between the two.
     #
     objects = workspace.object_set.get_objects(self.objects_name.value)
     labels = objects.segmented
     image = self.get_image(workspace)
     if self.show_window:
         # Save the image for display
         workspace.display_data.image = image
     #
     # Do a distance transform into the background to label points
     # in the background with their closest foreground object
     #
     i, j = scind.distance_transform_edt(labels==0, 
                                         return_indices=True,
                                         return_distances=False)
     confluent_labels = labels[i,j]
     confluent_labels[~mask] = 0
     if self.where_algorithm == CA_CLOSEST_POINT:
         #
         # For the closest point method, find the intensity at
         # the closest point in the object (which will be the point itself
         # for points in the object).
         # 
         object_intensity = image[i,j] * self.minimum_intensity_fraction.value
         confluent_labels[object_intensity > image] = 0
     count, index, c_j = morph.find_neighbors(confluent_labels)
     if len(c_j) == 0:
         # Nobody touches - return the labels matrix
         return labels
     #
     # Make a row of i matching the touching j
     #
     c_i = np.zeros(len(c_j))
     #
     # Eliminate labels without matches
     #
     label_numbers = np.arange(1,len(count)+1)[count > 0]
     index = index[count > 0]
     count = count[count > 0]
     #
     # Get the differences between labels so we can use a cumsum trick
     # to increment to the next label when they change
     #
     label_numbers[1:] = label_numbers[1:] - label_numbers[:-1]
     c_i[index] = label_numbers
     c_i = np.cumsum(c_i).astype(int)
     if self.where_algorithm == CA_CENTROIDS:
         #
         # Only connect points > minimum intensity fraction
         #
         center_i, center_j = morph.centers_of_labels(labels)
         indexes, counts, i, j = morph.get_line_pts(
             center_i[c_i-1], center_j[c_i-1],
             center_i[c_j-1], center_j[c_j-1])
         #
         # The indexes of the centroids at pt1
         #
         last_indexes = indexes+counts-1
         #
         # The minimum of the intensities at pt0 and pt1
         #
         centroid_intensities = np.minimum(
             image[i[indexes],j[indexes]],
             image[i[last_indexes], j[last_indexes]])
         #
         # Assign label numbers to each point so we can use
         # scipy.ndimage.minimum. The label numbers are indexes into
         # "connections" above.
         #
         pt_labels = np.zeros(len(i), int)
         pt_labels[indexes[1:]] = 1
         pt_labels = np.cumsum(pt_labels)
         minima = scind.minimum(image[i,j], pt_labels, np.arange(len(indexes)))
         minima = morph.fixup_scipy_ndimage_result(minima)
         #
         # Filter the connections using the image
         #
         mif = self.minimum_intensity_fraction.value
         i = c_i[centroid_intensities * mif <= minima]
         j = c_j[centroid_intensities * mif <= minima]
     else:
         i = c_i
         j = c_j
     #
     # Add in connections from self to self
     #
     unique_labels = np.unique(labels)
     i = np.hstack((i, unique_labels))
     j = np.hstack((j, unique_labels))
     #
     # Run "all_connected_components" to get a component # for
     # objects identified as same.
     #
     new_indexes = morph.all_connected_components(i, j)
     new_labels = np.zeros(labels.shape, int)
     new_labels[labels != 0] = new_indexes[labels[labels != 0]]
     return new_labels
Exemple #13
0
 def filter_using_image(self, workspace, mask):
     '''Filter out connections using local intensity minima between objects
     
     workspace - the workspace for the image set
     mask - mask of background points within the minimum distance
     '''
     #
     # NOTE: This is an efficient implementation and an improvement
     #       in accuracy over the Matlab version. It would be faster and
     #       more accurate to eliminate the line-connecting and instead
     #       do the following:
     #     * Distance transform to get the coordinates of the closest
     #       point in an object for points in the background that are
     #       at most 1/2 of the max distance between objects.
     #     * Take the intensity at this closest point and similarly
     #       label the background point if the background intensity
     #       is at least the minimum intensity fraction
     #     * Assume there is a connection between objects if, after this
     #       labeling, there are adjacent points in each object.
     #
     # As it is, the algorithm duplicates the Matlab version but suffers
     # for cells whose intensity isn't high in the centroid and clearly
     # suffers when two cells touch at some point that's off of the line
     # between the two.
     #
     objects = workspace.object_set.get_objects(self.objects_name.value)
     labels = objects.segmented
     image = self.get_image(workspace)
     if self.show_window:
         # Save the image for display
         workspace.display_data.image = image
     #
     # Do a distance transform into the background to label points
     # in the background with their closest foreground object
     #
     i, j = scind.distance_transform_edt(labels == 0,
                                         return_indices=True,
                                         return_distances=False)
     confluent_labels = labels[i, j]
     confluent_labels[~mask] = 0
     if self.where_algorithm == CA_CLOSEST_POINT:
         #
         # For the closest point method, find the intensity at
         # the closest point in the object (which will be the point itself
         # for points in the object).
         #
         object_intensity = image[i,
                                  j] * self.minimum_intensity_fraction.value
         confluent_labels[object_intensity > image] = 0
     count, index, c_j = morph.find_neighbors(confluent_labels)
     if len(c_j) == 0:
         # Nobody touches - return the labels matrix
         return labels
     #
     # Make a row of i matching the touching j
     #
     c_i = np.zeros(len(c_j))
     #
     # Eliminate labels without matches
     #
     label_numbers = np.arange(1, len(count) + 1)[count > 0]
     index = index[count > 0]
     count = count[count > 0]
     #
     # Get the differences between labels so we can use a cumsum trick
     # to increment to the next label when they change
     #
     label_numbers[1:] = label_numbers[1:] - label_numbers[:-1]
     c_i[index] = label_numbers
     c_i = np.cumsum(c_i).astype(int)
     if self.where_algorithm == CA_CENTROIDS:
         #
         # Only connect points > minimum intensity fraction
         #
         center_i, center_j = morph.centers_of_labels(labels)
         indexes, counts, i, j = morph.get_line_pts(center_i[c_i - 1],
                                                    center_j[c_i - 1],
                                                    center_i[c_j - 1],
                                                    center_j[c_j - 1])
         #
         # The indexes of the centroids at pt1
         #
         last_indexes = indexes + counts - 1
         #
         # The minimum of the intensities at pt0 and pt1
         #
         centroid_intensities = np.minimum(
             image[i[indexes], j[indexes]], image[i[last_indexes],
                                                  j[last_indexes]])
         #
         # Assign label numbers to each point so we can use
         # scipy.ndimage.minimum. The label numbers are indexes into
         # "connections" above.
         #
         pt_labels = np.zeros(len(i), int)
         pt_labels[indexes[1:]] = 1
         pt_labels = np.cumsum(pt_labels)
         minima = scind.minimum(image[i, j], pt_labels,
                                np.arange(len(indexes)))
         minima = morph.fixup_scipy_ndimage_result(minima)
         #
         # Filter the connections using the image
         #
         mif = self.minimum_intensity_fraction.value
         i = c_i[centroid_intensities * mif <= minima]
         j = c_j[centroid_intensities * mif <= minima]
     else:
         i = c_i
         j = c_j
     #
     # Add in connections from self to self
     #
     unique_labels = np.unique(labels)
     i = np.hstack((i, unique_labels))
     j = np.hstack((j, unique_labels))
     #
     # Run "all_connected_components" to get a component # for
     # objects identified as same.
     #
     new_indexes = morph.all_connected_components(i, j)
     new_labels = np.zeros(labels.shape, int)
     new_labels[labels != 0] = new_indexes[labels[labels != 0]]
     return new_labels
    def run(self, workspace):
        objects = workspace.object_set.get_objects(self.object_name.value)
        assert isinstance(objects, cpo.Objects)
        has_pixels = objects.areas > 0
        labels = objects.small_removed_segmented
        kept_labels = objects.segmented
        neighbor_objects = workspace.object_set.get_objects(self.neighbors_name.value)
        assert isinstance(neighbor_objects, cpo.Objects)
        neighbor_labels = neighbor_objects.small_removed_segmented
        #
        # Need to add in labels touching border.
        #
        unedited_segmented = neighbor_objects.unedited_segmented
        touching_border = np.zeros(np.max(unedited_segmented) + 1, bool)
        touching_border[unedited_segmented[0, :]] = True
        touching_border[unedited_segmented[-1, :]] = True
        touching_border[unedited_segmented[:, 0]] = True
        touching_border[unedited_segmented[:, -1]] = True
        touching_border[0] = False
        touching_border_mask = touching_border[unedited_segmented]
        nobjects = np.max(labels)
        nneighbors = np.max(neighbor_labels)
        nkept_objects = objects.count
        if np.any(touching_border) and \
           np.all(~ touching_border_mask[neighbor_labels!=0]):
            # Add the border labels if any were excluded
            touching_border_object_number = np.cumsum(touching_border) + \
                np.max(neighbor_labels)
            touching_border_mask = touching_border_mask & neighbor_labels == 0
            neighbor_labels = neighbor_labels.copy().astype(np.int32)
            neighbor_labels[touching_border_mask] = touching_border_object_number[
                unedited_segmented[touching_border_mask]]
        
        _, object_numbers = objects.relate_labels(labels, kept_labels)
        if self.neighbors_are_objects:
            neighbor_numbers = object_numbers
        else:
            _, neighbor_numbers = neighbor_objects.relate_labels(
                neighbor_labels, neighbor_objects.segmented)
        neighbor_count = np.zeros((nobjects,))
        pixel_count = np.zeros((nobjects,))
        first_object_number = np.zeros((nobjects,),int)
        second_object_number = np.zeros((nobjects,),int)
        first_x_vector = np.zeros((nobjects,))
        second_x_vector = np.zeros((nobjects,))
        first_y_vector = np.zeros((nobjects,))
        second_y_vector = np.zeros((nobjects,))
        angle = np.zeros((nobjects,))
        percent_touching = np.zeros((nobjects,))
        expanded_labels = None
        if self.distance_method == D_EXPAND:
            # Find the i,j coordinates of the nearest foreground point
            # to every background point
            i,j = scind.distance_transform_edt(labels==0,
                                               return_distances=False,
                                               return_indices=True)
            # Assign each background pixel to the label of its nearest
            # foreground pixel. Assign label to label for foreground.
            labels = labels[i,j]
            expanded_labels = labels  # for display
            distance = 1 # dilate once to make touching edges overlap
            scale = S_EXPANDED
            if self.neighbors_are_objects:
                neighbor_labels = labels.copy()
        elif self.distance_method == D_WITHIN:
            distance = self.distance.value
            scale = str(distance)
        elif self.distance_method == D_ADJACENT:
            distance = 1
            scale = S_ADJACENT
        else:
            raise ValueError("Unknown distance method: %s" %
                             self.distance_method.value)
        if nneighbors > (1 if self.neighbors_are_objects else 0):
            first_objects = []
            second_objects = []
            object_indexes = np.arange(nobjects, dtype=np.int32)+1
            #
            # First, compute the first and second nearest neighbors,
            # and the angles between self and the first and second
            # nearest neighbors
            #
            ocenters = centers_of_labels(
                objects.small_removed_segmented).transpose()
            ncenters = centers_of_labels(
                neighbor_objects.small_removed_segmented).transpose()
            areas = fix(scind.sum(np.ones(labels.shape),labels, object_indexes))
            perimeter_outlines = outline(labels)
            perimeters = fix(scind.sum(
                np.ones(labels.shape), perimeter_outlines, object_indexes))
                                       
            i,j = np.mgrid[0:nobjects,0:nneighbors]
            distance_matrix = np.sqrt((ocenters[i,0] - ncenters[j,0])**2 +
                                      (ocenters[i,1] - ncenters[j,1])**2)
            #
            # order[:,0] should be arange(nobjects)
            # order[:,1] should be the nearest neighbor
            # order[:,2] should be the next nearest neighbor
            #
            if distance_matrix.shape[1] == 1:
                # a little buggy, lexsort assumes that a 2-d array of
                # second dimension = 1 is a 1-d array
                order = np.zeros(distance_matrix.shape, int)
            else:
                order = np.lexsort([distance_matrix])
            first_neighbor = 1 if self.neighbors_are_objects else 0
            first_object_index = order[:, first_neighbor]
            first_x_vector = ncenters[first_object_index,1] - ocenters[:,1]
            first_y_vector = ncenters[first_object_index,0] - ocenters[:,0]
            if nneighbors > first_neighbor+1:
                second_object_index = order[:, first_neighbor + 1]
                second_x_vector = ncenters[second_object_index,1] - ocenters[:,1]
                second_y_vector = ncenters[second_object_index,0] - ocenters[:,0]
                v1 = np.array((first_x_vector,first_y_vector))
                v2 = np.array((second_x_vector,second_y_vector))
                #
                # Project the unit vector v1 against the unit vector v2
                #
                dot = (np.sum(v1*v2,0) / 
                       np.sqrt(np.sum(v1**2,0)*np.sum(v2**2,0)))
                angle = np.arccos(dot) * 180. / np.pi
            
            # Make the structuring element for dilation
            strel = strel_disk(distance)
            #
            # A little bigger one to enter into the border with a structure
            # that mimics the one used to create the outline
            #
            strel_touching = strel_disk(distance + .5)
            #
            # Get the extents for each object and calculate the patch
            # that excises the part of the image that is "distance"
            # away
            i,j = np.mgrid[0:labels.shape[0],0:labels.shape[1]]
            min_i, max_i, min_i_pos, max_i_pos =\
                scind.extrema(i,labels,object_indexes)
            min_j, max_j, min_j_pos, max_j_pos =\
                scind.extrema(j,labels,object_indexes)
            min_i = np.maximum(fix(min_i)-distance,0).astype(int)
            max_i = np.minimum(fix(max_i)+distance+1,labels.shape[0]).astype(int)
            min_j = np.maximum(fix(min_j)-distance,0).astype(int)
            max_j = np.minimum(fix(max_j)+distance+1,labels.shape[1]).astype(int)
            #
            # Loop over all objects
            # Calculate which ones overlap "index"
            # Calculate how much overlap there is of others to "index"
            #
            for object_number in object_numbers:
                if object_number == 0:
                    #
                    # No corresponding object in small-removed. This means
                    # that the object has no pixels, e.g. not renumbered.
                    #
                    continue
                index = object_number - 1
                patch = labels[min_i[index]:max_i[index],
                               min_j[index]:max_j[index]]
                npatch = neighbor_labels[min_i[index]:max_i[index],
                                         min_j[index]:max_j[index]]
                #
                # Find the neighbors
                #
                patch_mask = patch==(index+1)
                extended = scind.binary_dilation(patch_mask,strel)
                neighbors = np.unique(npatch[extended])
                neighbors = neighbors[neighbors != 0]
                if self.neighbors_are_objects:
                    neighbors = neighbors[neighbors != object_number]
                nc = len(neighbors)
                neighbor_count[index] = nc
                if nc > 0:
                    first_objects.append(np.ones(nc,int) * object_number)
                    second_objects.append(neighbors)
                if self.neighbors_are_objects:
                    #
                    # Find the # of overlapping pixels. Dilate the neighbors
                    # and see how many pixels overlap our image. Use a 3x3
                    # structuring element to expand the overlapping edge
                    # into the perimeter.
                    #
                    outline_patch = perimeter_outlines[
                        min_i[index]:max_i[index],
                        min_j[index]:max_j[index]] == object_number
                    extended = scind.binary_dilation(
                        (patch != 0) & (patch != object_number), strel_touching)
                    overlap = np.sum(outline_patch & extended)
                    pixel_count[index] = overlap
            if sum([len(x) for x in first_objects]) > 0:
                first_objects = np.hstack(first_objects)
                reverse_object_numbers = np.zeros(
                    max(np.max(object_numbers), np.max(first_objects)) + 1, int)
                reverse_object_numbers[object_numbers] = np.arange(len(object_numbers)) + 1
                first_objects = reverse_object_numbers[first_objects]
    
                second_objects = np.hstack(second_objects)
                reverse_neighbor_numbers = np.zeros(
                    max(np.max(neighbor_numbers), np.max(second_objects)) + 1, int)
                reverse_neighbor_numbers[neighbor_numbers] = np.arange(len(neighbor_numbers)) + 1
                second_objects= reverse_neighbor_numbers[second_objects]
                to_keep = (first_objects > 0) & (second_objects > 0)
                first_objects = first_objects[to_keep]
                second_objects  = second_objects[to_keep]
            else:
                first_objects = np.zeros(0, int)
                second_objects = np.zeros(0, int)
            if self.neighbors_are_objects:
                percent_touching = pixel_count * 100 / perimeters
            else:
                percent_touching = pixel_count * 100.0 / areas
            object_indexes = object_numbers - 1
            neighbor_indexes = neighbor_numbers - 1
            #
            # Have to recompute nearest
            #
            first_object_number = np.zeros(nkept_objects, int)
            second_object_number = np.zeros(nkept_objects, int)
            if nkept_objects > (1 if self.neighbors_are_objects else 0):
                di = (ocenters[object_indexes[:, np.newaxis], 0] - 
                      ncenters[neighbor_indexes[np.newaxis, :], 0])
                dj = (ocenters[object_indexes[:, np.newaxis], 1] - 
                      ncenters[neighbor_indexes[np.newaxis, :], 1])
                distance_matrix = np.sqrt(di*di + dj*dj)
                distance_matrix[~ has_pixels, :] = np.inf
                distance_matrix[:, ~has_pixels] = np.inf
                #
                # order[:,0] should be arange(nobjects)
                # order[:,1] should be the nearest neighbor
                # order[:,2] should be the next nearest neighbor
                #
                order = np.lexsort([distance_matrix]).astype(
                    first_object_number.dtype)
                if self.neighbors_are_objects:
                    first_object_number[has_pixels] = order[has_pixels,1] + 1
                    if nkept_objects > 2:
                        second_object_number[has_pixels] = order[has_pixels,2] + 1
                else:
                    first_object_number[has_pixels] = order[has_pixels,0] + 1
                    if nneighbors > 1:
                        second_object_number[has_pixels] = order[has_pixels,1] + 1
        else:
            object_indexes = object_numbers - 1
            neighbor_indexes = neighbor_numbers - 1
            first_objects = np.zeros(0, int)
            second_objects = np.zeros(0, int)
        #
        # Now convert all measurements from the small-removed to
        # the final number set.
        #
        neighbor_count = neighbor_count[object_indexes]
        neighbor_count[~ has_pixels] = 0
        percent_touching = percent_touching[object_indexes]
        percent_touching[~ has_pixels] = 0
        first_x_vector = first_x_vector[object_indexes]
        second_x_vector = second_x_vector[object_indexes]
        first_y_vector = first_y_vector[object_indexes]
        second_y_vector = second_y_vector[object_indexes]
        angle = angle[object_indexes]
        #
        # Record the measurements
        #
        assert(isinstance(workspace, cpw.Workspace))
        m = workspace.measurements
        assert(isinstance(m, cpmeas.Measurements))
        image_set = workspace.image_set
        features_and_data = [
            (M_NUMBER_OF_NEIGHBORS, neighbor_count),
            (M_FIRST_CLOSEST_OBJECT_NUMBER, first_object_number),
            (M_FIRST_CLOSEST_DISTANCE, np.sqrt(first_x_vector**2+first_y_vector**2)),
            (M_SECOND_CLOSEST_OBJECT_NUMBER, second_object_number),
            (M_SECOND_CLOSEST_DISTANCE, np.sqrt(second_x_vector**2+second_y_vector**2)),
            (M_ANGLE_BETWEEN_NEIGHBORS, angle)]
        if self.neighbors_are_objects:
            features_and_data.append((M_PERCENT_TOUCHING, percent_touching))
        for feature_name, data in features_and_data:
            m.add_measurement(self.object_name.value,
                              self.get_measurement_name(feature_name),
                              data)
        if len(first_objects) > 0:
            m.add_relate_measurement(
                self.module_num, 
                cpmeas.NEIGHBORS,
                self.object_name.value,
                self.object_name.value if self.neighbors_are_objects 
                else self.neighbors_name.value,
                m.image_set_number * np.ones(first_objects.shape, int),
                first_objects,
                m.image_set_number * np.ones(second_objects.shape, int),
                second_objects)
                                 
        labels = kept_labels
        
        neighbor_count_image = np.zeros(labels.shape,int)
        object_mask = objects.segmented != 0
        object_indexes = objects.segmented[object_mask]-1
        neighbor_count_image[object_mask] = neighbor_count[object_indexes]
        workspace.display_data.neighbor_count_image = neighbor_count_image
        
        if self.neighbors_are_objects:
            percent_touching_image = np.zeros(labels.shape)
            percent_touching_image[object_mask] = percent_touching[object_indexes]
            workspace.display_data.percent_touching_image = percent_touching_image
        
        image_set = workspace.image_set
        if self.wants_count_image.value:
            neighbor_cm_name = self.count_colormap.value
            neighbor_cm = get_colormap(neighbor_cm_name)
            sm = matplotlib.cm.ScalarMappable(cmap = neighbor_cm)
            img = sm.to_rgba(neighbor_count_image)[:,:,:3]
            img[:,:,0][~ object_mask] = 0
            img[:,:,1][~ object_mask] = 0
            img[:,:,2][~ object_mask] = 0
            count_image = cpi.Image(img, masking_objects = objects)
            image_set.add(self.count_image_name.value, count_image)
        else:
            neighbor_cm_name = cpprefs.get_default_colormap()
            neighbor_cm = matplotlib.cm.get_cmap(neighbor_cm_name)
        if self.neighbors_are_objects and self.wants_percent_touching_image:
            percent_touching_cm_name = self.touching_colormap.value
            percent_touching_cm = get_colormap(percent_touching_cm_name)
            sm = matplotlib.cm.ScalarMappable(cmap = percent_touching_cm)
            img = sm.to_rgba(percent_touching_image)[:,:,:3]
            img[:,:,0][~ object_mask] = 0
            img[:,:,1][~ object_mask] = 0
            img[:,:,2][~ object_mask] = 0
            touching_image = cpi.Image(img, masking_objects = objects)
            image_set.add(self.touching_image_name.value,
                          touching_image)
        else:
            percent_touching_cm_name = cpprefs.get_default_colormap()
            percent_touching_cm = matplotlib.cm.get_cmap(percent_touching_cm_name)

        if self.show_window:
            workspace.display_data.neighbor_cm_name = neighbor_cm_name
            workspace.display_data.percent_touching_cm_name = percent_touching_cm_name
            workspace.display_data.orig_labels = objects.segmented
            workspace.display_data.expanded_labels = expanded_labels
            workspace.display_data.object_mask = object_mask
 def do_measurements(self, workspace, image_name, object_name, 
                     center_object_name, bin_count,
                     dd):
     '''Perform the radial measurements on the image set
     
     workspace - workspace that holds images / objects
     image_name - make measurements on this image
     object_name - make measurements on these objects
     center_object_name - use the centers of these related objects as
                   the centers for radial measurements. None to use the
                   objects themselves.
     bin_count - bin the object into this many concentric rings
     d - a dictionary for saving reusable partial results
     
     returns one statistics tuple per ring.
     '''
     assert isinstance(workspace, cpw.Workspace)
     assert isinstance(workspace.object_set, cpo.ObjectSet)
     image = workspace.image_set.get_image(image_name,
                                           must_be_grayscale=True)
     objects = workspace.object_set.get_objects(object_name)
     labels, pixel_data = cpo.crop_labels_and_image(objects.segmented,
                                                    image.pixel_data)
     nobjects = np.max(objects.segmented)
     measurements = workspace.measurements
     assert isinstance(measurements, cpmeas.Measurements)
     if nobjects == 0:
         for bin in range(1, bin_count+1):
             for feature in (FF_FRAC_AT_D, FF_MEAN_FRAC, FF_RADIAL_CV):
                 measurements.add_measurement(object_name,
                                              M_CATEGORY + "_" + feature % 
                                              (image_name, bin, bin_count),
                                              np.zeros(0))
         return [(image_name, object_name, "no objects","-","-","-","-")]
     name = (object_name if center_object_name is None 
             else "%s_%s"%(object_name, center_object_name))
     if dd.has_key(name):
         normalized_distance, i_center, j_center, good_mask = dd[name]
     else:
         d_to_edge = distance_to_edge(labels)
         if center_object_name is not None:
             center_objects=workspace.object_set.get_objects(center_object_name)
             center_labels, cmask = cpo.size_similarly(
                 labels, center_objects.segmented)
             pixel_counts = fix(scind.sum(np.ones(center_labels.shape),
                                          center_labels,
                                          np.arange(1, np.max(center_labels)+1,dtype=np.int32)))
             good = pixel_counts > 0
             i,j = (centers_of_labels(center_labels) + .5).astype(int)
             ig = i[good]
             jg = j[good]
             center_labels = np.zeros(center_labels.shape, int)
             center_labels[ig,jg] = labels[ig,jg] ## TODO: This is incorrect when objects are annular.  Retrieves label# = 0
             cl,d_from_center = propagate(np.zeros(center_labels.shape),
                                          center_labels,
                                          labels != 0, 1)
         else:
             # Find the point in each object farthest away from the edge.
             # This does better than the centroid:
             # * The center is within the object
             # * The center tends to be an interesting point, like the
             #   center of the nucleus or the center of one or the other
             #   of two touching cells.
             #
             i,j = maximum_position_of_labels(d_to_edge, labels, objects.indices)
             center_labels = np.zeros(labels.shape, int)
             center_labels[i,j] = labels[i,j]
             #
             # Use the coloring trick here to process touching objects
             # in separate operations
             #
             colors = color_labels(labels)
             ncolors = np.max(colors)
             d_from_center = np.zeros(labels.shape)
             cl = np.zeros(labels.shape, int)
             for color in range(1,ncolors+1):
                 mask = colors == color
                 l,d = propagate(np.zeros(center_labels.shape),
                                 center_labels,
                                 mask, 1)
                 d_from_center[mask] = d[mask]
                 cl[mask] = l[mask]
         good_mask = cl > 0
         i_center = np.zeros(cl.shape)
         i_center[good_mask] = i[cl[good_mask]-1]
         j_center = np.zeros(cl.shape)
         j_center[good_mask] = j[cl[good_mask]-1]
         
         normalized_distance = np.zeros(labels.shape)
         total_distance = d_from_center + d_to_edge
         normalized_distance[good_mask] = (d_from_center[good_mask] /
                                           (total_distance[good_mask] + .001))
         dd[name] = [normalized_distance, i_center, j_center, good_mask]
     ngood_pixels = np.sum(good_mask)
     good_labels = objects.segmented[good_mask]
     bin_indexes = (normalized_distance * bin_count).astype(int)
     labels_and_bins = (good_labels-1,bin_indexes[good_mask])
     histogram = coo_matrix((image.pixel_data[good_mask], labels_and_bins),
                            (nobjects, bin_count)).toarray()
     sum_by_object = np.sum(histogram, 1)
     sum_by_object_per_bin = np.dstack([sum_by_object]*bin_count)[0]
     fraction_at_distance = histogram / sum_by_object_per_bin
     number_at_distance = coo_matrix((np.ones(ngood_pixels),labels_and_bins),
                                     (nobjects, bin_count)).toarray()
     object_mask = number_at_distance > 0
     sum_by_object = np.sum(number_at_distance, 1)
     sum_by_object_per_bin = np.dstack([sum_by_object]*bin_count)[0]
     fraction_at_bin = number_at_distance / sum_by_object_per_bin
     mean_pixel_fraction = fraction_at_distance / (fraction_at_bin +
                                                   np.finfo(float).eps)
     masked_fraction_at_distance = masked_array(fraction_at_distance,
                                                ~object_mask)
     masked_mean_pixel_fraction = masked_array(mean_pixel_fraction,
                                               ~object_mask)
     # Anisotropy calculation.  Split each cell into eight wedges, then
     # compute coefficient of variation of the wedges' mean intensities
     # in each ring.
     #
     # Compute each pixel's delta from the center object's centroid
     i,j = np.mgrid[0:labels.shape[0], 0:labels.shape[1]]
     imask = i[good_mask] > i_center[good_mask]
     jmask = j[good_mask] > j_center[good_mask]
     absmask = (abs(i[good_mask] - i_center[good_mask]) > 
                abs(j[good_mask] - j_center[good_mask]))
     radial_index = (imask.astype(int) + jmask.astype(int)*2 + 
                     absmask.astype(int)*4)
     statistics = []
     for bin in range(bin_count):
         bin_mask = (good_mask & (bin_indexes == bin))
         bin_pixels = np.sum(bin_mask)
         bin_labels = labels[bin_mask]
         bin_radial_index = radial_index[bin_indexes[good_mask] == bin]
         labels_and_radii = (bin_labels-1, bin_radial_index)
         radial_values = coo_matrix((pixel_data[bin_mask],
                                     labels_and_radii),
                                    (nobjects, 8)).toarray()
         pixel_count = coo_matrix((np.ones(bin_pixels), labels_and_radii),
                                  (nobjects, 8)).toarray()
         mask = pixel_count==0
         radial_means = masked_array(radial_values / pixel_count, mask)
         radial_cv = np.std(radial_means,1) / np.mean(radial_means, 1)
         radial_cv[np.sum(~mask,1)==0] = 0
         for measurement, feature in ((fraction_at_distance[:,bin], MF_FRAC_AT_D),
                                      (mean_pixel_fraction[:,bin], MF_MEAN_FRAC),
                                      (np.array(radial_cv), MF_RADIAL_CV)):
                                      
             measurements.add_measurement(object_name,
                                          feature % 
                                          (image_name, bin+1, bin_count),
                                          measurement)
         radial_cv.mask = np.sum(~mask,1)==0
         statistics += [(image_name, object_name, str(bin+1), str(bin_count),
                         round(np.mean(masked_fraction_at_distance[:,bin]),4),
                         round(np.mean(masked_mean_pixel_fraction[:, bin]),4),
                         round(np.mean(radial_cv),4))]
     return statistics
Exemple #16
0
 def calculate_minimum_distances(self, workspace, parent_name):
     '''Calculate the distance from child center to parent perimeter'''
     meas = workspace.measurements
     assert isinstance(meas, cpmeas.Measurements)
     sub_object_name = self.sub_object_name.value
     parents = workspace.object_set.get_objects(parent_name)
     children = workspace.object_set.get_objects(sub_object_name)
     parents_of = self.get_parents_of(workspace, parent_name)
     if len(parents_of) == 0:
         dist = np.zeros((0, ))
     elif np.all(parents_of == 0):
         dist = np.array([np.NaN] * len(parents_of))
     else:
         mask = parents_of > 0
         ccenters = centers_of_labels(children.segmented).transpose()
         ccenters = ccenters[mask, :]
         parents_of_masked = parents_of[mask] - 1
         pperim = outline(parents.segmented)
         #
         # Get a list of all points on the perimeter
         #
         perim_loc = np.argwhere(pperim != 0)
         #
         # Get the label # for each point
         #
         perim_idx = pperim[perim_loc[:, 0], perim_loc[:, 1]]
         #
         # Sort the points by label #
         #
         idx = np.lexsort((perim_loc[:, 1], perim_loc[:, 0], perim_idx))
         perim_loc = perim_loc[idx, :]
         perim_idx = perim_idx[idx]
         #
         # Get counts and indexes to each run of perimeter points
         #
         counts = fix(
             scind.sum(np.ones(len(perim_idx)), perim_idx,
                       np.arange(1, perim_idx[-1] + 1))).astype(np.int32)
         indexes = np.cumsum(counts) - counts
         #
         # For the children, get the index and count of the parent
         #
         ccounts = counts[parents_of_masked]
         cindexes = indexes[parents_of_masked]
         #
         # Now make an array that has an element for each of that child's
         # perimeter points
         #
         clabel = np.zeros(np.sum(ccounts), int)
         #
         # cfirst is the eventual first index of each child in the
         # clabel array
         #
         cfirst = np.cumsum(ccounts) - ccounts
         clabel[cfirst[1:]] += 1
         clabel = np.cumsum(clabel)
         #
         # Make an index that runs from 0 to ccounts for each
         # child label.
         #
         cp_index = np.arange(len(clabel)) - cfirst[clabel]
         #
         # then add cindexes to get an index to the perimeter point
         #
         cp_index += cindexes[clabel]
         #
         # Now, calculate the distance from the centroid of each label
         # to each perimeter point in the parent.
         #
         dist = np.sqrt(
             np.sum((perim_loc[cp_index, :] - ccenters[clabel, :])**2, 1))
         #
         # Finally, find the minimum distance per child
         #
         min_dist = fix(scind.minimum(dist, clabel,
                                      np.arange(len(ccounts))))
         #
         # Account for unparented children
         #
         dist = np.array([np.NaN] * len(mask))
         dist[mask] = min_dist
     meas.add_measurement(sub_object_name, FF_MINIMUM % parent_name, dist)
    def run(self, workspace):
        objects = workspace.object_set.get_objects(self.object_name.value)
        assert isinstance(objects, cpo.Objects)
        has_pixels = objects.areas > 0
        labels = objects.small_removed_segmented
        kept_labels = objects.segmented
        neighbor_objects = workspace.object_set.get_objects(self.neighbors_name.value)
        assert isinstance(neighbor_objects, cpo.Objects)
        neighbor_labels = neighbor_objects.small_removed_segmented
        #
        # Need to add in labels touching border.
        #
        unedited_segmented = neighbor_objects.unedited_segmented
        touching_border = np.zeros(np.max(unedited_segmented) + 1, bool)
        touching_border[unedited_segmented[0, :]] = True
        touching_border[unedited_segmented[-1, :]] = True
        touching_border[unedited_segmented[:, 0]] = True
        touching_border[unedited_segmented[:, -1]] = True
        touching_border[0] = False
        touching_border_mask = touching_border[unedited_segmented]
        if np.any(touching_border) and \
           np.all(~ touching_border_mask[neighbor_labels]):
            # Add the border labels if any were excluded
            touching_border_object_number = np.cumsum(touching_border) + \
                np.max(neighbor_labels)
            touching_border_mask = touching_border_mask & neighbor_labels == 0
            neighbor_labels[touching_border_mask] = touching_border_object_number[
                unedited_segmented[touching_border_mask]]
        
        nobjects = np.max(labels)
        nneighbors = np.max(neighbor_labels)
        nkept_objects = objects.count
        _, object_numbers = objects.relate_labels(labels, kept_labels)
        if self.neighbors_are_objects:
            neighbor_numbers = object_numbers
        else:
            _, neighbor_numbers = neighbor_objects.relate_labels(
                neighbor_labels, neighbor_objects.segmented)
        neighbor_count = np.zeros((nobjects,))
        pixel_count = np.zeros((nobjects,))
        first_object_number = np.zeros((nobjects,),int)
        second_object_number = np.zeros((nobjects,),int)
        first_x_vector = np.zeros((nobjects,))
        second_x_vector = np.zeros((nobjects,))
        first_y_vector = np.zeros((nobjects,))
        second_y_vector = np.zeros((nobjects,))
        angle = np.zeros((nobjects,))
        percent_touching = np.zeros((nobjects,))
        expanded_labels = None
        if self.distance_method == D_EXPAND:
            # Find the i,j coordinates of the nearest foreground point
            # to every background point
            i,j = scind.distance_transform_edt(labels==0,
                                               return_distances=False,
                                               return_indices=True)
            # Assign each background pixel to the label of its nearest
            # foreground pixel. Assign label to label for foreground.
            labels = labels[i,j]
            expanded_labels = labels  # for display
            distance = 1 # dilate once to make touching edges overlap
            scale = S_EXPANDED
            if self.neighbors_are_objects:
                neighbor_labels = labels.copy()
        elif self.distance_method == D_WITHIN:
            distance = self.distance.value
            scale = str(distance)
        elif self.distance_method == D_ADJACENT:
            distance = 1
            scale = S_ADJACENT
        else:
            raise ValueError("Unknown distance method: %s" %
                             self.distance_method.value)
        if nneighbors > (1 if self.neighbors_are_objects else 0):
            first_objects = []
            second_objects = []
            object_indexes = np.arange(nobjects, dtype=np.int32)+1
            #
            # First, compute the first and second nearest neighbors,
            # and the angles between self and the first and second
            # nearest neighbors
            #
            ocenters = centers_of_labels(
                objects.small_removed_segmented).transpose()
            ncenters = centers_of_labels(
                neighbor_objects.small_removed_segmented).transpose()
            areas = fix(scind.sum(np.ones(labels.shape),labels, object_indexes))
            perimeter_outlines = outline(labels)
            perimeters = fix(scind.sum(
                np.ones(labels.shape), perimeter_outlines, object_indexes))
                                       
            i,j = np.mgrid[0:nobjects,0:nneighbors]
            distance_matrix = np.sqrt((ocenters[i,0] - ncenters[j,0])**2 +
                                      (ocenters[i,1] - ncenters[j,1])**2)
            #
            # order[:,0] should be arange(nobjects)
            # order[:,1] should be the nearest neighbor
            # order[:,2] should be the next nearest neighbor
            #
            if distance_matrix.shape[1] == 1:
                # a little buggy, lexsort assumes that a 2-d array of
                # second dimension = 1 is a 1-d array
                order = np.zeros(distance_matrix.shape, int)
            else:
                order = np.lexsort([distance_matrix])
            first_neighbor = 1 if self.neighbors_are_objects else 0
            first_object_index = order[:, first_neighbor]
            first_x_vector = ncenters[first_object_index,1] - ocenters[:,1]
            first_y_vector = ncenters[first_object_index,0] - ocenters[:,0]
            if nneighbors > first_neighbor+1:
                second_object_index = order[:, first_neighbor + 1]
                second_x_vector = ncenters[second_object_index,1] - ocenters[:,1]
                second_y_vector = ncenters[second_object_index,0] - ocenters[:,0]
                v1 = np.array((first_x_vector,first_y_vector))
                v2 = np.array((second_x_vector,second_y_vector))
                #
                # Project the unit vector v1 against the unit vector v2
                #
                dot = (np.sum(v1*v2,0) / 
                       np.sqrt(np.sum(v1**2,0)*np.sum(v2**2,0)))
                angle = np.arccos(dot) * 180. / np.pi
            
            # Make the structuring element for dilation
            strel = strel_disk(distance)
            #
            # A little bigger one to enter into the border with a structure
            # that mimics the one used to create the outline
            #
            strel_touching = strel_disk(distance + .5)
            #
            # Get the extents for each object and calculate the patch
            # that excises the part of the image that is "distance"
            # away
            i,j = np.mgrid[0:labels.shape[0],0:labels.shape[1]]
            min_i, max_i, min_i_pos, max_i_pos =\
                scind.extrema(i,labels,object_indexes)
            min_j, max_j, min_j_pos, max_j_pos =\
                scind.extrema(j,labels,object_indexes)
            min_i = np.maximum(fix(min_i)-distance,0).astype(int)
            max_i = np.minimum(fix(max_i)+distance+1,labels.shape[0]).astype(int)
            min_j = np.maximum(fix(min_j)-distance,0).astype(int)
            max_j = np.minimum(fix(max_j)+distance+1,labels.shape[1]).astype(int)
            #
            # Loop over all objects
            # Calculate which ones overlap "index"
            # Calculate how much overlap there is of others to "index"
            #
            for object_number in object_numbers:
                if object_number == 0:
                    #
                    # No corresponding object in small-removed. This means
                    # that the object has no pixels, e.g. not renumbered.
                    #
                    continue
                index = object_number - 1
                patch = labels[min_i[index]:max_i[index],
                               min_j[index]:max_j[index]]
                npatch = neighbor_labels[min_i[index]:max_i[index],
                                         min_j[index]:max_j[index]]
                #
                # Find the neighbors
                #
                patch_mask = patch==(index+1)
                extended = scind.binary_dilation(patch_mask,strel)
                neighbors = np.unique(npatch[extended])
                neighbors = neighbors[neighbors != 0]
                if self.neighbors_are_objects:
                    neighbors = neighbors[neighbors != object_number]
                nc = len(neighbors)
                neighbor_count[index] = nc
                if nc > 0:
                    first_objects.append(np.ones(nc,int) * object_number)
                    second_objects.append(neighbors)
                if self.neighbors_are_objects:
                    #
                    # Find the # of overlapping pixels. Dilate the neighbors
                    # and see how many pixels overlap our image. Use a 3x3
                    # structuring element to expand the overlapping edge
                    # into the perimeter.
                    #
                    outline_patch = perimeter_outlines[
                        min_i[index]:max_i[index],
                        min_j[index]:max_j[index]] == object_number
                    extended = scind.binary_dilation(
                        (patch != 0) & (patch != object_number), strel_touching)
                    overlap = np.sum(outline_patch & extended)
                    pixel_count[index] = overlap
            if sum([len(x) for x in first_objects]) > 0:
                first_objects = np.hstack(first_objects)
                reverse_object_numbers = np.zeros(
                    max(np.max(object_numbers), np.max(first_objects)) + 1, int)
                reverse_object_numbers[object_numbers] = np.arange(len(object_numbers)) + 1
                first_objects = reverse_object_numbers[first_objects]
    
                second_objects = np.hstack(second_objects)
                reverse_neighbor_numbers = np.zeros(
                    max(np.max(neighbor_numbers), np.max(second_objects)) + 1, int)
                reverse_neighbor_numbers[neighbor_numbers] = np.arange(len(neighbor_numbers)) + 1
                second_objects= reverse_neighbor_numbers[second_objects]
                to_keep = (first_objects > 0) & (second_objects > 0)
                first_objects = first_objects[to_keep]
                second_objects  = second_objects[to_keep]
            else:
                first_objects = np.zeros(0, int)
                second_objects = np.zeros(0, int)
            if self.neighbors_are_objects:
                percent_touching = pixel_count * 100 / perimeters
            else:
                percent_touching = pixel_count * 100.0 / areas
            object_indexes = object_numbers - 1
            neighbor_indexes = neighbor_numbers - 1
            #
            # Have to recompute nearest
            #
            first_object_number = np.zeros(nkept_objects, int)
            second_object_number = np.zeros(nkept_objects, int)
            if nkept_objects > (1 if self.neighbors_are_objects else 0):
                di = (ocenters[object_indexes[:, np.newaxis], 0] - 
                      ncenters[neighbor_indexes[np.newaxis, :], 0])
                dj = (ocenters[object_indexes[:, np.newaxis], 1] - 
                      ncenters[neighbor_indexes[np.newaxis, :], 1])
                distance_matrix = np.sqrt(di*di + dj*dj)
                distance_matrix[~ has_pixels, :] = np.inf
                distance_matrix[:, ~has_pixels] = np.inf
                #
                # order[:,0] should be arange(nobjects)
                # order[:,1] should be the nearest neighbor
                # order[:,2] should be the next nearest neighbor
                #
                order = np.lexsort([distance_matrix]).astype(
                    first_object_number.dtype)
                if self.neighbors_are_objects:
                    first_object_number[has_pixels] = order[has_pixels,1] + 1
                    if nkept_objects > 2:
                        second_object_number[has_pixels] = order[has_pixels,2] + 1
                else:
                    first_object_number[has_pixels] = order[has_pixels,0] + 1
                    if nneighbors > 1:
                        second_object_number[has_pixels] = order[has_pixels,1] + 1
        else:
            object_indexes = object_numbers - 1
            neighbor_indexes = neighbor_numbers - 1
            first_objects = np.zeros(0, int)
            second_objects = np.zeros(0, int)
        #
        # Now convert all measurements from the small-removed to
        # the final number set.
        #
        neighbor_count = neighbor_count[object_indexes]
        neighbor_count[~ has_pixels] = 0
        percent_touching = percent_touching[object_indexes]
        percent_touching[~ has_pixels] = 0
        first_x_vector = first_x_vector[object_indexes]
        second_x_vector = second_x_vector[object_indexes]
        first_y_vector = first_y_vector[object_indexes]
        second_y_vector = second_y_vector[object_indexes]
        angle = angle[object_indexes]
        #
        # Record the measurements
        #
        assert(isinstance(workspace, cpw.Workspace))
        m = workspace.measurements
        assert(isinstance(m, cpmeas.Measurements))
        image_set = workspace.image_set
        features_and_data = [
            (M_NUMBER_OF_NEIGHBORS, neighbor_count),
            (M_FIRST_CLOSEST_OBJECT_NUMBER, first_object_number),
            (M_FIRST_CLOSEST_DISTANCE, np.sqrt(first_x_vector**2+first_y_vector**2)),
            (M_SECOND_CLOSEST_OBJECT_NUMBER, second_object_number),
            (M_SECOND_CLOSEST_DISTANCE, np.sqrt(second_x_vector**2+second_y_vector**2)),
            (M_ANGLE_BETWEEN_NEIGHBORS, angle)]
        if self.neighbors_are_objects:
            features_and_data.append((M_PERCENT_TOUCHING, percent_touching))
        for feature_name, data in features_and_data:
            m.add_measurement(self.object_name.value,
                              self.get_measurement_name(feature_name),
                              data)
        if len(first_objects) > 0:
            m.add_relate_measurement(
                self.module_num, 
                cpmeas.NEIGHBORS,
                self.object_name.value,
                self.object_name.value if self.neighbors_are_objects 
                else self.neighbors_name.value,
                m.image_set_number * np.ones(first_objects.shape, int),
                first_objects,
                m.image_set_number * np.ones(second_objects.shape, int),
                second_objects)
                                 
        labels = kept_labels
        
        neighbor_count_image = np.zeros(labels.shape,int)
        object_mask = objects.segmented != 0
        object_indexes = objects.segmented[object_mask]-1
        neighbor_count_image[object_mask] = neighbor_count[object_indexes]
        workspace.display_data.neighbor_count_image = neighbor_count_image
        
        if self.neighbors_are_objects:
            percent_touching_image = np.zeros(labels.shape)
            percent_touching_image[object_mask] = percent_touching[object_indexes]
            workspace.display_data.percent_touching_image = percent_touching_image
        
        image_set = workspace.image_set
        if self.wants_count_image.value:
            neighbor_cm_name = self.count_colormap.value
            neighbor_cm = get_colormap(neighbor_cm_name)
            sm = matplotlib.cm.ScalarMappable(cmap = neighbor_cm)
            img = sm.to_rgba(neighbor_count_image)[:,:,:3]
            img[:,:,0][~ object_mask] = 0
            img[:,:,1][~ object_mask] = 0
            img[:,:,2][~ object_mask] = 0
            count_image = cpi.Image(img, masking_objects = objects)
            image_set.add(self.count_image_name.value, count_image)
        else:
            neighbor_cm_name = cpprefs.get_default_colormap()
            neighbor_cm = matplotlib.cm.get_cmap(neighbor_cm_name)
        if self.neighbors_are_objects and self.wants_percent_touching_image:
            percent_touching_cm_name = self.touching_colormap.value
            percent_touching_cm = get_colormap(percent_touching_cm_name)
            sm = matplotlib.cm.ScalarMappable(cmap = percent_touching_cm)
            img = sm.to_rgba(percent_touching_image)[:,:,:3]
            img[:,:,0][~ object_mask] = 0
            img[:,:,1][~ object_mask] = 0
            img[:,:,2][~ object_mask] = 0
            touching_image = cpi.Image(img, masking_objects = objects)
            image_set.add(self.touching_image_name.value,
                          touching_image)
        else:
            percent_touching_cm_name = cpprefs.get_default_colormap()
            percent_touching_cm = matplotlib.cm.get_cmap(percent_touching_cm_name)

        if self.show_window:
            workspace.display_data.neighbor_cm_name = neighbor_cm_name
            workspace.display_data.percent_touching_cm_name = percent_touching_cm_name
            workspace.display_data.orig_labels = objects.segmented
            workspace.display_data.expanded_labels = expanded_labels
            workspace.display_data.object_mask = object_mask
 def calculate_minimum_distances(self, workspace, parent_name):
     '''Calculate the distance from child center to parent perimeter'''
     meas = workspace.measurements
     assert isinstance(meas,cpmeas.Measurements)
     sub_object_name = self.sub_object_name.value
     parents = workspace.object_set.get_objects(parent_name)
     children = workspace.object_set.get_objects(sub_object_name)
     parents_of = self.get_parents_of(workspace, parent_name)
     if len(parents_of) == 0:
         dist = np.zeros((0,))
     elif np.all(parents_of == 0):
         dist = np.array([np.NaN] * len(parents_of))
     else:
         mask = parents_of > 0
         ccenters = centers_of_labels(children.segmented).transpose()
         ccenters = ccenters[mask,:]
         parents_of_masked = parents_of[mask] - 1
         pperim = outline(parents.segmented)
         #
         # Get a list of all points on the perimeter
         #
         perim_loc = np.argwhere(pperim != 0)
         #
         # Get the label # for each point
         #
         perim_idx = pperim[perim_loc[:,0],perim_loc[:,1]]
         #
         # Sort the points by label #
         #
         idx = np.lexsort((perim_loc[:,1],perim_loc[:,0],perim_idx))
         perim_loc = perim_loc[idx,:]
         perim_idx = perim_idx[idx]
         #
         # Get counts and indexes to each run of perimeter points
         #
         counts = fix(scind.sum(np.ones(len(perim_idx)),perim_idx,
                                np.arange(1,perim_idx[-1]+1))).astype(np.int32)
         indexes = np.cumsum(counts) - counts
         #
         # For the children, get the index and count of the parent
         #
         ccounts = counts[parents_of_masked]
         cindexes = indexes[parents_of_masked]
         #
         # Now make an array that has an element for each of that child's
         # perimeter points
         #
         clabel = np.zeros(np.sum(ccounts), int)
         #
         # cfirst is the eventual first index of each child in the
         # clabel array
         #
         cfirst = np.cumsum(ccounts) - ccounts
         clabel[cfirst[1:]] += 1
         clabel = np.cumsum(clabel)
         #
         # Make an index that runs from 0 to ccounts for each
         # child label.
         #
         cp_index = np.arange(len(clabel)) - cfirst[clabel]
         #
         # then add cindexes to get an index to the perimeter point
         #
         cp_index += cindexes[clabel]
         #
         # Now, calculate the distance from the centroid of each label
         # to each perimeter point in the parent.
         #
         dist = np.sqrt(np.sum((perim_loc[cp_index,:] - 
                                ccenters[clabel,:])**2,1))
         #
         # Finally, find the minimum distance per child
         #
         min_dist = fix(scind.minimum(dist, clabel, np.arange(len(ccounts))))
         #
         # Account for unparented children
         #
         dist = np.array([np.NaN] * len(mask))
         dist[mask] = min_dist
     meas.add_measurement(sub_object_name, FF_MINIMUM % parent_name, dist)