示例#1
0
    def __init__(self, mode):
        """
        :param mode: train2014 or val2014
        """
        self.mode = mode
        self.root = os.path.join(COCO_PATH, mode)
        self.ann_file = os.path.join(COCO_PATH, 'annotations',
                                     'instances_{}.json'.format(mode))
        self.coco = COCO(self.ann_file)
        self.ids = [
            k for k in self.coco.imgs.keys() if len(self.coco.imgToAnns[k]) > 0
        ]

        tform = []
        if self.is_train:
            tform.append(
                RandomOrder([
                    Grayscale(),
                    Brightness(),
                    Contrast(),
                    Sharpness(),
                    Hue(),
                ]))

        tform += [
            SquarePad(),
            Resize(IM_SCALE),
            ToTensor(),
            Normalize(mean=[0.485, 0.456, 0.406], std=[0.229, 0.224, 0.225]),
        ]

        self.transform_pipeline = Compose(tform)
        self.ind_to_classes = ['__background__'] + [
            v['name'] for k, v in self.coco.cats.items()
        ]
        # COCO inds are weird (84 inds in total but a bunch of numbers are skipped)
        self.id_to_ind = {
            coco_id: (ind + 1)
            for ind, coco_id in enumerate(self.coco.cats.keys())
        }
        self.id_to_ind[0] = 0

        self.ind_to_id = {x: y for y, x in self.id_to_ind.items()}
 def coco(self):
     """
     :return: a Coco-like object that we can use to evaluate detection!
     """
     anns = []
     for i, (cls_array,
             box_array) in enumerate(zip(self.gt_classes, self.gt_boxes)):
         for cls, box in zip(cls_array.tolist(), box_array.tolist()):
             anns.append({
                 'area': (box[3] - box[1] + 1) * (box[2] - box[0] + 1),
                 'bbox':
                 [box[0], box[1], box[2] - box[0] + 1, box[3] - box[1] + 1],
                 'category_id':
                 cls,
                 'id':
                 len(anns),
                 'image_id':
                 i,
                 'iscrowd':
                 0,
             })
     fauxcoco = COCO()
     fauxcoco.dataset = {
         'info': {
             'description': 'ayy lmao'
         },
         'images': [{
             'id': i
         } for i in range(self.__len__())],
         'categories': [{
             'supercategory': 'person',
             'id': i,
             'name': name
         } for i, name in enumerate(self.ind_to_classes)
                        if name != '__background__'],
         'annotations':
         anns,
     }
     fauxcoco.createIndex()
     return fauxcoco
示例#3
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  def __init__(self, image_set, year):
    imdb.__init__(self, 'coco_' + year + '_' + image_set)
    # COCO specific config options
    self.config = {'use_salt': True,
                   'cleanup': True}
    # name, paths
    self._year = year
    self._image_set = image_set
    self._data_path = osp.join(cfg.DATA_DIR, 'coco')
    # load COCO API, classes, class <-> id mappings
    self._COCO = COCO(self._get_ann_file())
    cats = self._COCO.loadCats(self._COCO.getCatIds())
    self._classes = tuple(['__background__'] + [c['name'] for c in cats])
    self._class_to_ind = dict(list(zip(self.classes, list(range(self.num_classes)))))
    self._class_to_coco_cat_id = dict(list(zip([c['name'] for c in cats],
                                               self._COCO.getCatIds())))
    self._image_index = self._load_image_set_index()
    # Default to roidb handler
    self.set_proposal_method('gt')
    self.competition_mode(False)

    # Some image sets are "views" (i.e. subsets) into others.
    # For example, minival2014 is a random 5000 image subset of val2014.
    # This mapping tells us where the view's images and proposals come from.
    self._view_map = {
      'minival2014': 'val2014',  # 5k val2014 subset
      'valminusminival2014': 'val2014',  # val2014 \setminus minival2014
      'test-dev2015': 'test2015',
      'valminuscapval2014': 'val2014',
      'capval2014': 'val2014',
      'captest2014': 'val2014'
    }
    coco_name = image_set + year  # e.g., "val2014"
    self._data_name = (self._view_map[coco_name]
                       if coco_name in self._view_map
                       else coco_name)
    # Dataset splits that have ground-truth annotations (test splits
    # do not have gt annotations)
    self._gt_splits = ('train', 'val', 'minival')
示例#4
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class coco(imdb):
    def __init__(self, image_set, year):
        imdb.__init__(self, 'coco_' + year + '_' + image_set)
        # COCO specific config options
        self.config = {'use_salt': True, 'cleanup': True}
        # name, paths
        self._year = year
        self._image_set = image_set
        self._data_path = osp.join(cfg.DATA_DIR, 'coco')
        # load COCO API, classes, class <-> id mappings
        self._COCO = COCO(self._get_ann_file())
        cats = self._COCO.loadCats(self._COCO.getCatIds())
        self._classes = tuple(['__background__'] + [c['name'] for c in cats])
        self._class_to_ind = dict(
            list(zip(self.classes, list(range(self.num_classes)))))
        self._class_to_coco_cat_id = dict(
            list(zip([c['name'] for c in cats], self._COCO.getCatIds())))
        self._image_index = self._load_image_set_index()
        # Default to roidb handler
        self.set_proposal_method('gt')
        self.competition_mode(False)

        # Some image sets are "views" (i.e. subsets) into others.
        # For example, minival2014 is a random 5000 image subset of val2014.
        # This mapping tells us where the view's images and proposals come from.
        self._view_map = {
            'minival2014': 'val2014',  # 5k val2014 subset
            'valminusminival2014': 'val2014',  # val2014 \setminus minival2014
            'test-dev2015': 'test2015',
            'valminuscapval2014': 'val2014',
            'capval2014': 'val2014',
            'captest2014': 'val2014'
        }
        coco_name = image_set + year  # e.g., "val2014"
        self._data_name = (self._view_map[coco_name]
                           if coco_name in self._view_map else coco_name)
        # Dataset splits that have ground-truth annotations (test splits
        # do not have gt annotations)
        self._gt_splits = ('train', 'val', 'minival')

    def _get_ann_file(self):
        prefix = 'instances' if self._image_set.find('test') == -1 \
          else 'image_info'
        return osp.join(self._data_path, 'annotations',
                        prefix + '_' + self._image_set + self._year + '.json')

    def _load_image_set_index(self):
        """
    Load image ids.
    """
        image_ids = self._COCO.getImgIds()
        return image_ids

    def _get_widths(self):
        anns = self._COCO.loadImgs(self._image_index)
        widths = [ann['width'] for ann in anns]
        return widths

    def image_path_at(self, i):
        """
    Return the absolute path to image i in the image sequence.
    """
        return self.image_path_from_index(self._image_index[i])

    def image_id_at(self, i):
        """
    Return the absolute path to image i in the image sequence.
    """
        return self._image_index[i]

    def image_path_from_index(self, index):
        """
    Construct an image path from the image's "index" identifier.
    """
        # Example image path for index=119993:
        #   images/train2014/COCO_train2014_000000119993.jpg
        file_name = ('COCO_' + self._data_name + '_' + str(index).zfill(12) +
                     '.jpg')
        image_path = osp.join(self._data_path, 'images', self._data_name,
                              file_name)
        assert osp.exists(image_path), \
          'Path does not exist: {}'.format(image_path)
        return image_path

    def gt_roidb(self):
        """
    Return the database of ground-truth regions of interest.
    This function loads/saves from/to a cache file to speed up future calls.
    """
        cache_file = osp.join(self.cache_path, self.name + '_gt_roidb.pkl')
        if osp.exists(cache_file):
            with open(cache_file, 'rb') as fid:
                roidb = pickle.load(fid)
            print('{} gt roidb loaded from {}'.format(self.name, cache_file))
            return roidb

        gt_roidb = [
            self._load_coco_annotation(index) for index in self._image_index
        ]

        with open(cache_file, 'wb') as fid:
            pickle.dump(gt_roidb, fid, pickle.HIGHEST_PROTOCOL)
        print('wrote gt roidb to {}'.format(cache_file))
        return gt_roidb

    def _load_coco_annotation(self, index):
        """
    Loads COCO bounding-box instance annotations. Crowd instances are
    handled by marking their overlaps (with all categories) to -1. This
    overlap value means that crowd "instances" are excluded from training.
    """
        im_ann = self._COCO.loadImgs(index)[0]
        width = im_ann['width']
        height = im_ann['height']

        annIds = self._COCO.getAnnIds(imgIds=index, iscrowd=None)
        objs = self._COCO.loadAnns(annIds)
        # Sanitize bboxes -- some are invalid
        valid_objs = []
        for obj in objs:
            x1 = np.max((0, obj['bbox'][0]))
            y1 = np.max((0, obj['bbox'][1]))
            x2 = np.min((width - 1, x1 + np.max((0, obj['bbox'][2] - 1))))
            y2 = np.min((height - 1, y1 + np.max((0, obj['bbox'][3] - 1))))
            if obj['area'] > 0 and x2 >= x1 and y2 >= y1:
                obj['clean_bbox'] = [x1, y1, x2, y2]
                valid_objs.append(obj)
        objs = valid_objs
        num_objs = len(objs)

        boxes = np.zeros((num_objs, 4), dtype=np.uint16)
        gt_classes = np.zeros((num_objs), dtype=np.int32)
        overlaps = np.zeros((num_objs, self.num_classes), dtype=np.float32)
        seg_areas = np.zeros((num_objs), dtype=np.float32)

        # Lookup table to map from COCO category ids to our internal class
        # indices
        coco_cat_id_to_class_ind = dict([(self._class_to_coco_cat_id[cls],
                                          self._class_to_ind[cls])
                                         for cls in self._classes[1:]])

        for ix, obj in enumerate(objs):
            cls = coco_cat_id_to_class_ind[obj['category_id']]
            boxes[ix, :] = obj['clean_bbox']
            gt_classes[ix] = cls
            seg_areas[ix] = obj['area']
            if obj['iscrowd']:
                # Set overlap to -1 for all classes for crowd objects
                # so they will be excluded during training
                overlaps[ix, :] = -1.0
            else:
                overlaps[ix, cls] = 1.0

        ds_utils.validate_boxes(boxes, width=width, height=height)
        overlaps = scipy.sparse.csr_matrix(overlaps)
        return {
            'width': width,
            'height': height,
            'boxes': boxes,
            'gt_classes': gt_classes,
            'gt_overlaps': overlaps,
            'flipped': False,
            'seg_areas': seg_areas
        }

    def _get_widths(self):
        return [r['width'] for r in self.roidb]

    def append_flipped_images(self):
        num_images = self.num_images
        widths = self._get_widths()
        for i in range(num_images):
            boxes = self.roidb[i]['boxes'].copy()
            oldx1 = boxes[:, 0].copy()
            oldx2 = boxes[:, 2].copy()
            boxes[:, 0] = widths[i] - oldx2 - 1
            boxes[:, 2] = widths[i] - oldx1 - 1
            assert (boxes[:, 2] >= boxes[:, 0]).all()
            entry = {
                'width': widths[i],
                'height': self.roidb[i]['height'],
                'boxes': boxes,
                'gt_classes': self.roidb[i]['gt_classes'],
                'gt_overlaps': self.roidb[i]['gt_overlaps'],
                'flipped': True,
                'seg_areas': self.roidb[i]['seg_areas']
            }

            self.roidb.append(entry)
        self._image_index = self._image_index * 2

    def _get_box_file(self, index):
        # first 14 chars / first 22 chars / all chars + .mat
        # COCO_val2014_0/COCO_val2014_000000447/COCO_val2014_000000447991.mat
        file_name = ('COCO_' + self._data_name + '_' + str(index).zfill(12) +
                     '.mat')
        return osp.join(file_name[:14], file_name[:22], file_name)

    def _print_detection_eval_metrics(self, coco_eval):
        IoU_lo_thresh = 0.5
        IoU_hi_thresh = 0.95

        def _get_thr_ind(coco_eval, thr):
            ind = np.where((coco_eval.params.iouThrs > thr - 1e-5)
                           & (coco_eval.params.iouThrs < thr + 1e-5))[0][0]
            iou_thr = coco_eval.params.iouThrs[ind]
            assert np.isclose(iou_thr, thr)
            return ind

        ind_lo = _get_thr_ind(coco_eval, IoU_lo_thresh)
        ind_hi = _get_thr_ind(coco_eval, IoU_hi_thresh)
        # precision has dims (iou, recall, cls, area range, max dets)
        # area range index 0: all area ranges
        # max dets index 2: 100 per image
        precision = \
          coco_eval.eval['precision'][ind_lo:(ind_hi + 1), :, :, 0, 2]
        ap_default = np.mean(precision[precision > -1])
        print(('~~~~ Mean and per-category AP @ IoU=[{:.2f},{:.2f}] '
               '~~~~').format(IoU_lo_thresh, IoU_hi_thresh))
        print('{:.1f}'.format(100 * ap_default))
        for cls_ind, cls in enumerate(self.classes):
            if cls == '__background__':
                continue
            # minus 1 because of __background__
            precision = coco_eval.eval['precision'][ind_lo:(ind_hi + 1), :,
                                                    cls_ind - 1, 0, 2]
            ap = np.mean(precision[precision > -1])
            print('{:.1f}'.format(100 * ap))

        print('~~~~ Summary metrics ~~~~')
        coco_eval.summarize()

    def _do_detection_eval(self, res_file, output_dir):
        ann_type = 'bbox'
        coco_dt = self._COCO.loadRes(res_file)
        coco_eval = COCOeval(self._COCO, coco_dt)
        coco_eval.params.useSegm = (ann_type == 'segm')
        coco_eval.evaluate()
        coco_eval.accumulate()
        self._print_detection_eval_metrics(coco_eval)
        eval_file = osp.join(output_dir, 'detection_results.pkl')
        with open(eval_file, 'wb') as fid:
            pickle.dump(coco_eval, fid, pickle.HIGHEST_PROTOCOL)
        print('Wrote COCO eval results to: {}'.format(eval_file))

    def _coco_results_one_category(self, boxes, cat_id):
        results = []
        for im_ind, index in enumerate(self.image_index):
            dets = boxes[im_ind].astype(np.float)
            if dets == []:
                continue
            scores = dets[:, -1]
            xs = dets[:, 0]
            ys = dets[:, 1]
            ws = dets[:, 2] - xs + 1
            hs = dets[:, 3] - ys + 1
            results.extend([{
                'image_id': index,
                'category_id': cat_id,
                'bbox': [xs[k], ys[k], ws[k], hs[k]],
                'score': scores[k]
            } for k in range(dets.shape[0])])
        return results

    def _write_coco_results_file(self, all_boxes, res_file):
        # [{"image_id": 42,
        #   "category_id": 18,
        #   "bbox": [258.15,41.29,348.26,243.78],
        #   "score": 0.236}, ...]
        results = []
        for cls_ind, cls in enumerate(self.classes):
            if cls == '__background__':
                continue
            print('Collecting {} results ({:d}/{:d})'.format(
                cls, cls_ind, self.num_classes - 1))
            coco_cat_id = self._class_to_coco_cat_id[cls]
            results.extend(
                self._coco_results_one_category(all_boxes[cls_ind],
                                                coco_cat_id))
        print('Writing results json to {}'.format(res_file))
        with open(res_file, 'w') as fid:
            json.dump(results, fid)

    def evaluate_detections(self, all_boxes, output_dir):
        res_file = osp.join(
            output_dir,
            ('detections_' + self._image_set + self._year + '_results'))
        if self.config['use_salt']:
            res_file += '_{}'.format(str(uuid.uuid4()))
        res_file += '.json'
        self._write_coco_results_file(all_boxes, res_file)
        # Only do evaluation on non-test sets
        if self._image_set.find('test') == -1:
            self._do_detection_eval(res_file, output_dir)
        # Optionally cleanup results json file
        if self.config['cleanup']:
            os.remove(res_file)

    def competition_mode(self, on):
        if on:
            self.config['use_salt'] = False
            self.config['cleanup'] = False
        else:
            self.config['use_salt'] = True
            self.config['cleanup'] = True
示例#5
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    def load_coco(self,
                  dataset_dir,
                  subsets,
                  class_ids=None,
                  class_map=None,
                  return_coco=False):
        """Load a subset of the COCO dataset.
        dataset_dir: The root directory of the COCO dataset.
        subset: What to load (train, val, minival, val35k)
        class_ids: If provided, only loads images that have the given classes.
        class_map: TODO: Not implemented yet. Supports maping classes from
            different datasets to the same class ID.
        return_coco: If True, returns the COCO object.
        """
        # Path
        self._view_map = {
            'minival2014': 'val2014',  # 5k val2014 subset
            'valminusminival2014': 'val2014',  # val2014 \setminus minival2014
            'test-dev2015': 'test2015',
        }
        self.image_ids = []
        for subset in subsets:

            image_dir = os.path.join(
                dataset_dir, 'images',
                "train2014" if subset == "train" else "val2014")

            # Create COCO object
            json_path_dict = {
                "train": "annotations/instances_train2014.json",
                "val": "annotations/instances_val2014.json",
                "minival": "annotations/instances_minival2014.json",
                "val35k": "annotations/instances_valminusminival2014.json",
            }
            coco = COCO(os.path.join(dataset_dir, json_path_dict[subset]))
            image_ids = []
            # Load all classes or a subset?
            if not class_ids:
                # All classes
                class_ids = sorted(coco.getCatIds())

            # All images or a subset?
            if class_ids:
                for id in class_ids:
                    image_ids.extend(list(coco.getImgIds(catIds=[id])))
                # Remove duplicates
                image_ids = list(set(image_ids))
            else:
                # All images
                image_ids = list(coco.imgs.keys())

            # Add classes
            for i in class_ids:
                self.add_class("coco", i, coco.loadCats(i)[0]["name"])

            # Add images
            self.image_ids += image_ids
            for i in image_ids:
                self.add_image("coco",
                               image_id=i,
                               path=os.path.join(image_dir,
                                                 coco.imgs[i]['file_name']),
                               width=coco.imgs[i]["width"],
                               height=coco.imgs[i]["height"],
                               annotations=coco.loadAnns(
                                   coco.getAnnIds(imgIds=[i],
                                                  catIds=class_ids,
                                                  iscrowd=None)))
            print(subset)
            print(len(self.image_info))
        if return_coco:
            return coco
示例#6
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class CocoDetection(Dataset):
    """
    Adapted from the torchvision code
    """
    def __init__(self, mode):
        """
        :param mode: train2014 or val2014
        """
        self.mode = mode
        self.root = os.path.join(COCO_PATH, mode)
        self.ann_file = os.path.join(COCO_PATH, 'annotations',
                                     'instances_{}.json'.format(mode))
        self.coco = COCO(self.ann_file)
        self.ids = [
            k for k in self.coco.imgs.keys() if len(self.coco.imgToAnns[k]) > 0
        ]

        tform = []
        if self.is_train:
            tform.append(
                RandomOrder([
                    Grayscale(),
                    Brightness(),
                    Contrast(),
                    Sharpness(),
                    Hue(),
                ]))

        tform += [
            SquarePad(),
            Resize(IM_SCALE),
            ToTensor(),
            Normalize(mean=[0.485, 0.456, 0.406], std=[0.229, 0.224, 0.225]),
        ]

        self.transform_pipeline = Compose(tform)
        self.ind_to_classes = ['__background__'] + [
            v['name'] for k, v in self.coco.cats.items()
        ]
        # COCO inds are weird (84 inds in total but a bunch of numbers are skipped)
        self.id_to_ind = {
            coco_id: (ind + 1)
            for ind, coco_id in enumerate(self.coco.cats.keys())
        }
        self.id_to_ind[0] = 0

        self.ind_to_id = {x: y for y, x in self.id_to_ind.items()}

    @property
    def is_train(self):
        return self.mode.startswith('train')

    def __getitem__(self, index):
        """
        Args:
            index (int): Index

        Returns: entry dict
        """
        img_id = self.ids[index]
        path = self.coco.loadImgs(img_id)[0]['file_name']
        image_unpadded = Image.open(os.path.join(self.root,
                                                 path)).convert('RGB')
        ann_ids = self.coco.getAnnIds(imgIds=img_id)
        anns = self.coco.loadAnns(ann_ids)
        gt_classes = np.array([self.id_to_ind[x['category_id']] for x in anns],
                              dtype=np.int64)

        if np.any(gt_classes >= len(self.ind_to_classes)):
            raise ValueError("OH NO {}".format(index))

        if len(anns) == 0:
            raise ValueError("Annotations should not be empty")
        #     gt_boxes = np.array((0, 4), dtype=np.float32)
        # else:
        gt_boxes = np.array([x['bbox'] for x in anns], dtype=np.float32)

        if np.any(gt_boxes[:, [0, 1]] < 0):
            raise ValueError("GT boxes empty columns")
        if np.any(gt_boxes[:, [2, 3]] < 0):
            raise ValueError("GT boxes empty h/w")
        gt_boxes[:, [2, 3]] += gt_boxes[:, [0, 1]]

        # Rescale so that the boxes are at BOX_SCALE
        if self.is_train:
            image_unpadded, gt_boxes = random_crop(
                image_unpadded,
                gt_boxes * BOX_SCALE / max(image_unpadded.size),
                BOX_SCALE,
                round_boxes=False,
            )
        else:
            # Seems a bit silly because we won't be using GT boxes then but whatever
            gt_boxes = gt_boxes * BOX_SCALE / max(image_unpadded.size)
        w, h = image_unpadded.size
        box_scale_factor = BOX_SCALE / max(w, h)

        # Optionally flip the image if we're doing training
        flipped = self.is_train and np.random.random() > 0.5
        if flipped:
            scaled_w = int(box_scale_factor * float(w))
            image_unpadded = image_unpadded.transpose(Image.FLIP_LEFT_RIGHT)
            gt_boxes[:, [0, 2]] = scaled_w - gt_boxes[:, [2, 0]]

        img_scale_factor = IM_SCALE / max(w, h)
        if h > w:
            im_size = (IM_SCALE, int(w * img_scale_factor), img_scale_factor)
        elif h < w:
            im_size = (int(h * img_scale_factor), IM_SCALE, img_scale_factor)
        else:
            im_size = (IM_SCALE, IM_SCALE, img_scale_factor)

        entry = {
            'img': self.transform_pipeline(image_unpadded),
            'img_size': im_size,
            'gt_boxes': gt_boxes,
            'gt_classes': gt_classes,
            'scale': IM_SCALE / BOX_SCALE,
            'index': index,
            'image_id': img_id,
            'flipped': flipped,
            'fn': path,
        }

        return entry

    @classmethod
    def splits(cls, *args, **kwargs):
        """ Helper method to generate splits of the dataset"""
        train = cls('train2014', *args, **kwargs)
        val = cls('val2014', *args, **kwargs)
        return train, val

    def __len__(self):
        return len(self.ids)
示例#7
0
    def load_coco(self,
                  dataset_dir,
                  subset,
                  year=DEFAULT_DATASET_YEAR,
                  class_ids=None,
                  class_map=None,
                  return_coco=False,
                  auto_download=False):
        """Load a subset of the COCO dataset.
        dataset_dir: The root directory of the COCO dataset.
        subset: What to load (train, val, minival, valminusminival)
        year: What dataset year to load (2014, 2017) as a string, not an integer
        class_ids: If provided, only loads images that have the given classes.
        class_map: TODO: Not implemented yet. Supports maping classes from
            different datasets to the same class ID.
        return_coco: If True, returns the COCO object.
        auto_download: Automatically download and unzip MS-COCO images and annotations
        """

        if auto_download is True:
            self.auto_download(dataset_dir, subset, year)

        coco = COCO("{}/annotations/instances_{}{}.json".format(
            dataset_dir, subset, year))
        if subset == "minival" or subset == "valminusminival":
            subset = "val"
        image_dir = "{}/{}{}".format(dataset_dir, subset, year)

        # Load all classes or a subset?
        if not class_ids:
            # All classes
            class_ids = sorted(coco.getCatIds())

        # All images or a subset?
        if class_ids:
            image_ids = []
            for id in class_ids:
                image_ids.extend(list(coco.getImgIds(catIds=[id])))
            # Remove duplicates
            image_ids = list(set(image_ids))
        else:
            # All images
            image_ids = list(coco.imgs.keys())

        # Add classes
        for i in class_ids:
            self.add_class("coco", i, coco.loadCats(i)[0]["name"])

        # Add images
        for i in image_ids:
            self.add_image("coco",
                           image_id=i,
                           path=os.path.join(image_dir,
                                             coco.imgs[i]['file_name']),
                           width=coco.imgs[i]["width"],
                           height=coco.imgs[i]["height"],
                           annotations=coco.loadAnns(
                               coco.getAnnIds(imgIds=[i],
                                              catIds=class_ids,
                                              iscrowd=None)))
        if return_coco:
            return coco
示例#8
0
文件: coco.py 项目: meppe/ros-ort
class coco(imdb):
    def __init__(self, image_set, year):
        imdb.__init__(self, 'coco_' + year + '_' + image_set)
        # COCO specific config options
        self.config = {
            'top_k': 2000,
            'use_salt': True,
            'cleanup': True,
            'crowd_thresh': 0.7,
            'min_size': 2
        }
        # name, paths
        self._year = year
        self._image_set = image_set
        self._data_path = osp.join(cfg.DATA_DIR, 'coco')
        # load COCO API, classes, class <-> id mappings
        self._COCO = COCO(self._get_ann_file())
        cats = self._COCO.loadCats(self._COCO.getCatIds())
        self._classes = tuple(['__background__'] + [c['name'] for c in cats])
        self._class_to_ind = dict(zip(self.classes, xrange(self.num_classes)))
        self._class_to_coco_cat_id = dict(
            zip([c['name'] for c in cats], self._COCO.getCatIds()))
        self._image_index = self._load_image_set_index()
        # Default to roidb handler
        self.set_proposal_method('selective_search')
        self.competition_mode(False)

        # Some image sets are "views" (i.e. subsets) into others.
        # For example, minival2014 is a random 5000 image subset of val2014.
        # This mapping tells us where the view's images and proposals come from.
        self._view_map = {
            'minival2014': 'val2014',  # 5k val2014 subset
            'valminusminival2014': 'val2014',  # val2014 \setminus minival2014
        }
        coco_name = image_set + year  # e.g., "val2014"
        self._data_name = (self._view_map[coco_name]
                           if self._view_map.has_key(coco_name) else coco_name)
        # Dataset splits that have ground-truth annotations (test splits
        # do not have gt annotations)
        self._gt_splits = ('train', 'val', 'minival')

    def _get_ann_file(self):
        prefix = 'instances' if self._image_set.find('test') == -1 \
                             else 'image_info'
        return osp.join(self._data_path, 'annotations',
                        prefix + '_' + self._image_set + self._year + '.json')

    def _load_image_set_index(self):
        """
        Load image ids.
        """
        image_ids = self._COCO.getImgIds()
        return image_ids

    def _get_widths(self):
        anns = self._COCO.loadImgs(self._image_index)
        widths = [ann['width'] for ann in anns]
        return widths

    def image_path_at(self, i):
        """
        Return the absolute path to image i in the image sequence.
        """
        return self.image_path_from_index(self._image_index[i])

    def image_path_from_index(self, index):
        """
        Construct an image path from the image's "index" identifier.
        """
        # Example image path for index=119993:
        #   images/train2014/COCO_train2014_000000119993.jpg
        file_name = ('COCO_' + self._data_name + '_' + str(index).zfill(12) +
                     '.jpg')
        image_path = osp.join(self._data_path, 'images', self._data_name,
                              file_name)
        assert osp.exists(image_path), \
                'Path does not exist: {}'.format(image_path)
        return image_path

    def selective_search_roidb(self):
        return self._roidb_from_proposals('selective_search')

    def edge_boxes_roidb(self):
        return self._roidb_from_proposals('edge_boxes_AR')

    def mcg_roidb(self):
        return self._roidb_from_proposals('MCG')

    def _roidb_from_proposals(self, method):
        """
        Creates a roidb from pre-computed proposals of a particular methods.
        """
        top_k = self.config['top_k']
        cache_file = osp.join(
            self.cache_path,
            self.name + '_{:s}_top{:d}'.format(method, top_k) + '_roidb.pkl')

        if osp.exists(cache_file):
            with open(cache_file, 'rb') as fid:
                roidb = cPickle.load(fid)
            print '{:s} {:s} roidb loaded from {:s}'.format(
                self.name, method, cache_file)
            return roidb

        if self._image_set in self._gt_splits:
            gt_roidb = self.gt_roidb()
            method_roidb = self._load_proposals(method, gt_roidb)
            roidb = imdb.merge_roidbs(gt_roidb, method_roidb)
            # Make sure we don't use proposals that are contained in crowds
            roidb = _filter_crowd_proposals(roidb, self.config['crowd_thresh'])
        else:
            roidb = self._load_proposals(method, None)
        with open(cache_file, 'wb') as fid:
            cPickle.dump(roidb, fid, cPickle.HIGHEST_PROTOCOL)
        print 'wrote {:s} roidb to {:s}'.format(method, cache_file)
        return roidb

    def _load_proposals(self, method, gt_roidb):
        """
        Load pre-computed proposals in the format provided by Jan Hosang:
        http://www.mpi-inf.mpg.de/departments/computer-vision-and-multimodal-
          computing/research/object-recognition-and-scene-understanding/how-
          good-are-detection-proposals-really/
        For MCG, use boxes from http://www.eecs.berkeley.edu/Research/Projects/
          CS/vision/grouping/mcg/ and convert the file layout using
        lib/datasets/tools/mcg_munge.py.
        """
        box_list = []
        top_k = self.config['top_k']
        valid_methods = [
            'MCG', 'selective_search', 'edge_boxes_AR', 'edge_boxes_70'
        ]
        assert method in valid_methods

        print 'Loading {} boxes'.format(method)
        for i, index in enumerate(self._image_index):
            if i % 1000 == 0:
                print '{:d} / {:d}'.format(i + 1, len(self._image_index))

            box_file = osp.join(cfg.DATA_DIR, 'coco_proposals', method, 'mat',
                                self._get_box_file(index))

            raw_data = sio.loadmat(box_file)['boxes']
            boxes = np.maximum(raw_data - 1, 0).astype(np.uint16)
            if method == 'MCG':
                # Boxes from the MCG website are in (y1, x1, y2, x2) order
                boxes = boxes[:, (1, 0, 3, 2)]
            # Remove duplicate boxes and very small boxes and then take top k
            keep = ds_utils.unique_boxes(boxes)
            boxes = boxes[keep, :]
            keep = ds_utils.filter_small_boxes(boxes, self.config['min_size'])
            boxes = boxes[keep, :]
            boxes = boxes[:top_k, :]
            box_list.append(boxes)
            # Sanity check
            im_ann = self._COCO.loadImgs(index)[0]
            width = im_ann['width']
            height = im_ann['height']
            ds_utils.validate_boxes(boxes, width=width, height=height)
        return self.create_roidb_from_box_list(box_list, gt_roidb)

    def gt_roidb(self):
        """
        Return the database of ground-truth regions of interest.
        This function loads/saves from/to a cache file to speed up future calls.
        """
        cache_file = osp.join(self.cache_path, self.name + '_gt_roidb.pkl')
        if osp.exists(cache_file):
            with open(cache_file, 'rb') as fid:
                roidb = cPickle.load(fid)
            print '{} gt roidb loaded from {}'.format(self.name, cache_file)
            return roidb

        gt_roidb = [
            self._load_coco_annotation(index) for index in self._image_index
        ]

        with open(cache_file, 'wb') as fid:
            cPickle.dump(gt_roidb, fid, cPickle.HIGHEST_PROTOCOL)
        print 'wrote gt roidb to {}'.format(cache_file)
        return gt_roidb

    def _load_coco_annotation(self, index):
        """
        Loads COCO bounding-box instance annotations. Crowd instances are
        handled by marking their overlaps (with all categories) to -1. This
        overlap value means that crowd "instances" are excluded from training.
        """
        im_ann = self._COCO.loadImgs(index)[0]
        width = im_ann['width']
        height = im_ann['height']

        annIds = self._COCO.getAnnIds(imgIds=index, iscrowd=None)
        objs = self._COCO.loadAnns(annIds)
        # Sanitize bboxes -- some are invalid
        valid_objs = []
        for obj in objs:
            x1 = np.max((0, obj['bbox'][0]))
            y1 = np.max((0, obj['bbox'][1]))
            x2 = np.min((width - 1, x1 + np.max((0, obj['bbox'][2] - 1))))
            y2 = np.min((height - 1, y1 + np.max((0, obj['bbox'][3] - 1))))
            if obj['area'] > 0 and x2 >= x1 and y2 >= y1:
                obj['clean_bbox'] = [x1, y1, x2, y2]
                valid_objs.append(obj)
        objs = valid_objs
        num_objs = len(objs)

        boxes = np.zeros((num_objs, 4), dtype=np.uint16)
        gt_classes = np.zeros((num_objs), dtype=np.int32)
        overlaps = np.zeros((num_objs, self.num_classes), dtype=np.float32)
        seg_areas = np.zeros((num_objs), dtype=np.float32)

        # Lookup table to map from COCO category ids to our internal class
        # indices
        coco_cat_id_to_class_ind = dict([(self._class_to_coco_cat_id[cls],
                                          self._class_to_ind[cls])
                                         for cls in self._classes[1:]])

        for ix, obj in enumerate(objs):
            cls = coco_cat_id_to_class_ind[obj['category_id']]
            boxes[ix, :] = obj['clean_bbox']
            gt_classes[ix] = cls
            seg_areas[ix] = obj['area']
            if obj['iscrowd']:
                # Set overlap to -1 for all classes for crowd objects
                # so they will be excluded during training
                overlaps[ix, :] = -1.0
            else:
                overlaps[ix, cls] = 1.0

        ds_utils.validate_boxes(boxes, width=width, height=height)
        overlaps = scipy.sparse.csr_matrix(overlaps)
        return {
            'boxes': boxes,
            'gt_classes': gt_classes,
            'gt_overlaps': overlaps,
            'flipped': False,
            'seg_areas': seg_areas
        }

    def _get_box_file(self, index):
        # first 14 chars / first 22 chars / all chars + .mat
        # COCO_val2014_0/COCO_val2014_000000447/COCO_val2014_000000447991.mat
        file_name = ('COCO_' + self._data_name + '_' + str(index).zfill(12) +
                     '.mat')
        return osp.join(file_name[:14], file_name[:22], file_name)

    def _print_detection_eval_metrics(self, coco_eval):
        IoU_lo_thresh = 0.5
        IoU_hi_thresh = 0.95

        def _get_thr_ind(coco_eval, thr):
            ind = np.where((coco_eval.params.iouThrs > thr - 1e-5)
                           & (coco_eval.params.iouThrs < thr + 1e-5))[0][0]
            iou_thr = coco_eval.params.iouThrs[ind]
            assert np.isclose(iou_thr, thr)
            return ind

        ind_lo = _get_thr_ind(coco_eval, IoU_lo_thresh)
        ind_hi = _get_thr_ind(coco_eval, IoU_hi_thresh)
        # precision has dims (iou, recall, cls, area range, max dets)
        # area range index 0: all area ranges
        # max dets index 2: 100 per image
        precision = \
            coco_eval.eval['precision'][ind_lo:(ind_hi + 1), :, :, 0, 2]
        ap_default = np.mean(precision[precision > -1])
        print('~~~~ Mean and per-category AP @ IoU=[{:.2f},{:.2f}] '
              '~~~~').format(IoU_lo_thresh, IoU_hi_thresh)
        print '{:.1f}'.format(100 * ap_default)
        for cls_ind, cls in enumerate(self.classes):
            if cls == '__background__':
                continue
            # minus 1 because of __background__
            precision = coco_eval.eval['precision'][ind_lo:(ind_hi + 1), :,
                                                    cls_ind - 1, 0, 2]
            ap = np.mean(precision[precision > -1])
            print '{:.1f}'.format(100 * ap)

        print '~~~~ Summary metrics ~~~~'
        coco_eval.summarize()

    def _do_detection_eval(self, res_file, output_dir):
        ann_type = 'bbox'
        coco_dt = self._COCO.loadRes(res_file)
        coco_eval = COCOeval(self._COCO, coco_dt)
        coco_eval.params.useSegm = (ann_type == 'segm')
        coco_eval.evaluate()
        coco_eval.accumulate()
        self._print_detection_eval_metrics(coco_eval)
        eval_file = osp.join(output_dir, 'detection_results.pkl')
        with open(eval_file, 'wb') as fid:
            cPickle.dump(coco_eval, fid, cPickle.HIGHEST_PROTOCOL)
        print 'Wrote COCO eval results to: {}'.format(eval_file)

    def _coco_results_one_category(self, boxes, cat_id):
        results = []
        for im_ind, index in enumerate(self.image_index):
            dets = boxes[im_ind].astype(np.float)
            if dets == []:
                continue
            scores = dets[:, -1]
            xs = dets[:, 0]
            ys = dets[:, 1]
            ws = dets[:, 2] - xs + 1
            hs = dets[:, 3] - ys + 1
            results.extend([{
                'image_id': index,
                'category_id': cat_id,
                'bbox': [xs[k], ys[k], ws[k], hs[k]],
                'score': scores[k]
            } for k in xrange(dets.shape[0])])
        return results

    def _write_coco_results_file(self, all_boxes, res_file):
        # [{"image_id": 42,
        #   "category_id": 18,
        #   "bbox": [258.15,41.29,348.26,243.78],
        #   "score": 0.236}, ...]
        results = []
        for cls_ind, cls in enumerate(self.classes):
            if cls == '__background__':
                continue
            print 'Collecting {} results ({:d}/{:d})'.format(
                cls, cls_ind, self.num_classes - 1)
            coco_cat_id = self._class_to_coco_cat_id[cls]
            results.extend(
                self._coco_results_one_category(all_boxes[cls_ind],
                                                coco_cat_id))
        print 'Writing results json to {}'.format(res_file)
        with open(res_file, 'w') as fid:
            json.dump(results, fid)

    def evaluate_detections(self, all_boxes, output_dir):
        res_file = osp.join(
            output_dir,
            ('detections_' + self._image_set + self._year + '_results'))
        if self.config['use_salt']:
            res_file += '_{}'.format(str(uuid.uuid4()))
        res_file += '.json'
        self._write_coco_results_file(all_boxes, res_file)
        # Only do evaluation on non-test sets
        if self._image_set.find('test') == -1:
            self._do_detection_eval(res_file, output_dir)
        # Optionally cleanup results json file
        if self.config['cleanup']:
            os.remove(res_file)

    def competition_mode(self, on):
        if on:
            self.config['use_salt'] = False
            self.config['cleanup'] = False
        else:
            self.config['use_salt'] = True
            self.config['cleanup'] = True