class HistogramItem(GraphicsWidget):
"""
This is a graphicsWidget which provides controls for adjusting the display of an image.
Includes:
- Image histogram
- Movable region over histogram to select black/white levels
Parameters
----------
image : ImageItem or None
If *image* is provided, then the control will be automatically linked to
the image and changes to the control will be immediately reflected in
the image's appearance.
fillHistogram : bool
By default, the histogram is rendered with a fill.
For performance, set *fillHistogram* = False.
"""
sigLevelsChanged = pyqtSignal(object)
sigLevelChangeFinished = pyqtSignal(object)
def __init__(self, image=None, fillHistogram=True, bounds: tuple = None):
GraphicsWidget.__init__(self)
self.imageItem = lambda: None # fake a dead weakref
self.layout = QGraphicsGridLayout()
self.setLayout(self.layout)
self.layout.setContentsMargins(1, 1, 1, 1)
self.layout.setSpacing(0)
self.vb = ViewBox(parent=self)
# self.vb.setMaximumHeight(152)
# self.vb.setMinimumWidth(45)
self.vb.setMouseEnabled(x=True, y=False)
self.region = LinearRegionItem([0, 1], 'vertical', swapMode='block', bounds=bounds)
self.region.setZValue(1000)
self.vb.addItem(self.region)
self.region.lines[0].addMarker('<|', 0.5)
self.region.lines[1].addMarker('|>', 0.5)
self.region.sigRegionChanged.connect(self.regionChanging)
self.region.sigRegionChangeFinished.connect(self.regionChanged)
self.axis = AxisItem('bottom', linkView=self.vb, maxTickLength=-10, parent=self)
self.layout.addItem(self.axis, 1, 0)
self.layout.addItem(self.vb, 0, 0)
self.range = None
self.vb.sigRangeChanged.connect(self.viewRangeChanged)
self.plot = PlotCurveItem(pen=(200, 200, 200, 100))
# self.plot.rotate(90)
self.vb.addItem(self.plot)
self.fillHistogram(fillHistogram)
self._showRegions()
self.autoHistogramRange()
if image is not None:
self.setImageItem(image)
def fillHistogram(self, fill=True, level=0.0, color=(100, 100, 200)):
if fill:
self.plot.setFillLevel(level)
self.plot.setBrush(color)
else:
self.plot.setFillLevel(None)
def paint(self, p, *args):
rgn = self.getLevels()
self.vb.mapFromViewToItem(self, Point(self.vb.viewRect().center().x(), rgn[0]))
self.vb.mapFromViewToItem(self, Point(self.vb.viewRect().center().x(), rgn[1]))
def setHistogramRange(self, mn, mx, padding=0.1):
"""Set the Y range on the histogram plot. This disables auto-scaling."""
self.vb.enableAutoRange(self.vb.XAxis, False)
self.vb.setYRange(mn, mx, padding)
def autoHistogramRange(self):
"""Enable auto-scaling on the histogram plot."""
self.vb.enableAutoRange(self.vb.XYAxes)
def setImageItem(self, img):
"""Set an ImageItem to have its levels and LUT automatically controlled
by this HistogramLUTItem.
"""
self.imageItem = weakref.ref(img)
img.sigImageChanged.connect(self.imageChanged)
self.regionChanged()
self.imageChanged(autoLevel=True)
def viewRangeChanged(self):
self.update()
def regionChanged(self):
if self.imageItem() is not None:
self.imageItem().setLevels(self.getLevels())
self.sigLevelChangeFinished.emit(self)
def regionChanging(self):
if self.imageItem() is not None:
self.imageItem().setLevels(self.getLevels())
self.sigLevelsChanged.emit(self)
self.update()
def imageChanged(self, autoLevel=False):
if self.imageItem() is None:
return
self.plot.setVisible(True)
# plot one histogram for all image data
h = self.imageItem().getHistogram()
if h[0] is None:
return
self.plot.setData(*h)
if autoLevel:
mn = h[0][0]
mx = h[0][-1]
self.region.setRegion([mn, mx])
else:
mn, mx = self.imageItem().levels
self.region.setRegion([mn, mx])
def getLevels(self):
"""
Return the min and max levels.
"""
return self.region.getRegion()
def setLevels(self, min=None, max=None):
"""
Set the min/max (bright and dark) levels.
"""
assert None not in (min, max)
self.region.setRegion((min, max))
def _showRegions(self):
self.region.setVisible(True)
def saveState(self):
return {
'levels': self.getLevels(),
}
def restoreState(self, state):
self.setLevels(*state['levels'])
app = QtGui.QApplication([]) window = QMainWindow() holder = QWidget() holder_layout = QGridLayout() holder.setLayout(holder_layout) window.setCentralWidget(holder) # # Grid section # grid_widget = pg.GraphicsLayoutWidget() grid_viewBox1 = ViewBox(enableMenu=True) grid_viewBox1.setXRange(0, 5, padding=0) grid_viewBox1.setYRange(0, 2.5, padding=0) grid_subplot1 = PlotItem(viewBox=grid_viewBox1) grid_subplot1.showGrid(True, True, 0.2) grid_viewBox1.setParent(grid_subplot1) grid_widget.addItem(grid_subplot1, col=0, row=0) grid_viewBox2 = ViewBox(enableMenu=True) grid_viewBox2.setXRange(0, 5, padding=0) grid_viewBox2.setYRange(0, 2.5, padding=0) grid_subplot2 = PlotItem(viewBox=grid_viewBox2) grid_subplot2.showGrid(True, True, 0.2) grid_viewBox2.setParent(grid_subplot2) grid_widget.addItem(grid_subplot2, col=1, row=0) grid_viewBox3 = ViewBox(enableMenu=True) grid_viewBox3.setXRange(0, 5, padding=0)
class HistogramLUTItem_overlay(GraphicsWidget):
"""
This is a graphicsWidget which provides controls for adjusting the display of an image.
Includes:
- Image histogram
- Movable region over histogram to select black/white levels
- Gradient editor to define color lookup table for single-channel images
Parameters
----------
image : ImageItem or None
If *image* is provided, then the control will be automatically linked to
the image and changes to the control will be immediately reflected in
the image's appearance.
fillHistogram : bool
By default, the histogram is rendered with a fill.
For performance, set *fillHistogram* = False.
rgbHistogram : bool
Sets whether the histogram is computed once over all channels of the
image, or once per channel.
levelMode : 'mono' or 'rgba'
If 'mono', then only a single set of black/whilte level lines is drawn,
and the levels apply to all channels in the image. If 'rgba', then one
set of levels is drawn for each channel.
"""
sigLookupTableChanged = QtCore.Signal(object)
sigLevelsChanged = QtCore.Signal(object)
sigLevelChangeFinished = QtCore.Signal(object)
def __init__(self, image=None, fillHistogram=True, rgbHistogram=False, levelMode='mono'):
GraphicsWidget.__init__(self)
self.overlay = False
self.lut = None
self.imageItem = lambda: None # fake a dead weakref
self.levelMode = levelMode
self.rgbHistogram = rgbHistogram
self.layout = QtGui.QGraphicsGridLayout()
self.setLayout(self.layout)
self.layout.setContentsMargins(1,1,1,1)
self.layout.setSpacing(0)
self.vb = ViewBox(parent=self)
self.vb.setMaximumWidth(152)
self.vb.setMinimumWidth(45)
self.vb.setMouseEnabled(x=False, y=True)
self.gradient = GradientEditorItem()
self.gradient.setOrientation('right')
self.gradient.loadPreset('grey')
self.regions = [
LinearRegionItem([0, 1], 'horizontal', swapMode='block'),
LinearRegionItem([0, 1], 'horizontal', swapMode='block', pen='r',
brush=fn.mkBrush((255, 50, 50, 50)), span=(0., 1/3.)),
LinearRegionItem([0, 1], 'horizontal', swapMode='block', pen='g',
brush=fn.mkBrush((50, 255, 50, 50)), span=(1/3., 2/3.)),
LinearRegionItem([0, 1], 'horizontal', swapMode='block', pen='b',
brush=fn.mkBrush((50, 50, 255, 80)), span=(2/3., 1.)),
LinearRegionItem([0, 1], 'horizontal', swapMode='block', pen='w',
brush=fn.mkBrush((255, 255, 255, 50)), span=(2/3., 1.))]
for region in self.regions:
region.setZValue(1000)
self.vb.addItem(region)
region.lines[0].addMarker('<|', 0.5)
region.lines[1].addMarker('|>', 0.5)
region.sigRegionChanged.connect(self.regionChanging)
region.sigRegionChangeFinished.connect(self.regionChanged)
self.region = self.regions[0] # for backward compatibility.
self.axis = AxisItem('left', linkView=self.vb, maxTickLength=-10, parent=self)
self.layout.addItem(self.axis, 0, 0)
self.layout.addItem(self.vb, 0, 1)
self.layout.addItem(self.gradient, 0, 2)
self.range = None
self.gradient.setFlag(self.gradient.ItemStacksBehindParent)
self.vb.setFlag(self.gradient.ItemStacksBehindParent)
self.gradient.sigGradientChanged.connect(self.gradientChanged)
self.vb.sigRangeChanged.connect(self.viewRangeChanged)
add = QtGui.QPainter.CompositionMode_Plus
self.plots = [
PlotCurveItem(pen=(200, 200, 200, 100)), # mono
PlotCurveItem(pen=(255, 0, 0, 100), compositionMode=add), # r
PlotCurveItem(pen=(0, 255, 0, 100), compositionMode=add), # g
PlotCurveItem(pen=(0, 0, 255, 100), compositionMode=add), # b
PlotCurveItem(pen=(200, 200, 200, 100), compositionMode=add), # a
]
self.plot = self.plots[0] # for backward compatibility.
for plot in self.plots:
plot.rotate(90)
self.vb.addItem(plot)
self.fillHistogram(fillHistogram)
self._showRegions()
self.vb.addItem(self.plot)
self.autoHistogramRange()
if image is not None:
self.setImageItem(image)
def fillHistogram(self, fill=True, level=0.0, color=(100, 100, 200)):
colors = [color, (255, 0, 0, 50), (0, 255, 0, 50), (0, 0, 255, 50), (255, 255, 255, 50)]
for i,plot in enumerate(self.plots):
if fill:
plot.setFillLevel(level)
plot.setBrush(colors[i])
else:
plot.setFillLevel(None)
def paint(self, p, *args):
if self.levelMode != 'mono':
return
pen = self.region.lines[0].pen
rgn = self.getLevels()
p1 = self.vb.mapFromViewToItem(self, Point(self.vb.viewRect().center().x(), rgn[0]))
p2 = self.vb.mapFromViewToItem(self, Point(self.vb.viewRect().center().x(), rgn[1]))
gradRect = self.gradient.mapRectToParent(self.gradient.gradRect.rect())
for pen in [fn.mkPen((0, 0, 0, 100), width=3), pen]:
p.setPen(pen)
p.drawLine(p1 + Point(0, 5), gradRect.bottomLeft())
p.drawLine(p2 - Point(0, 5), gradRect.topLeft())
p.drawLine(gradRect.topLeft(), gradRect.topRight())
p.drawLine(gradRect.bottomLeft(), gradRect.bottomRight())
def setHistogramRange(self, mn, mx, padding=0.1):
"""Set the Y range on the histogram plot. This disables auto-scaling."""
self.vb.enableAutoRange(self.vb.YAxis, False)
self.vb.setYRange(mn, mx, padding)
def autoHistogramRange(self):
"""Enable auto-scaling on the histogram plot."""
self.vb.enableAutoRange(self.vb.XYAxes)
def setImageItem(self, img):
"""Set an ImageItem to have its levels and LUT automatically controlled
by this HistogramLUTItem.
"""
self.imageItem = weakref.ref(img)
img.sigImageChanged.connect(self.imageChanged)
img.setLookupTable(self.getLookupTable) ## send function pointer, not the result
self.regionChanged()
self.imageChanged(autoLevel=True)
def viewRangeChanged(self):
self.update()
def gradientChanged(self):
if self.imageItem() is not None:
if self.gradient.isLookupTrivial():
self.imageItem().setLookupTable(None) #lambda x: x.astype(np.uint8))
else:
self.imageItem().setLookupTable(self.getLookupTable) ## send function pointer, not the result
self.lut = None
self.sigLookupTableChanged.emit(self)
def getLookupTable(self, img=None, n=None, alpha=None):
"""Return a lookup table from the color gradient defined by this
HistogramLUTItem.
"""
if self.levelMode is not 'mono':
return None
if n is None:
if img.dtype == np.uint8:
n = 256
else:
n = 512
if self.lut is None:
self.lut = self.gradient.getLookupTable(n, alpha=alpha)
return self.lut
def regionChanged(self):
if self.imageItem() is not None:
self.imageItem().setLevels(self.getLevels())
self.sigLevelChangeFinished.emit(self)
def regionChanging(self):
if self.imageItem() is not None:
self.imageItem().setLevels(self.getLevels())
self.sigLevelsChanged.emit(self)
self.update()
def imageChanged(self, autoLevel=False, autoRange=False):
if self.imageItem() is None:
return
if self.levelMode == 'mono':
for plt in self.plots[1:]:
plt.setVisible(False)
self.plots[0].setVisible(True)
# plot one histogram for all image data
profiler = debug.Profiler()
h = self.imageItem().getHistogram()
profiler('get histogram')
if h[0] is None:
return
self.plot.setData(*h)
profiler('set plot')
if autoLevel:
mn = h[0][0]
mx = h[0][-1]
self.region.setRegion([mn, mx])
profiler('set region')
else:
mn, mx = self.imageItem().levels
self.region.setRegion([mn, mx])
else:
# plot one histogram for each channel
self.plots[0].setVisible(False)
ch = self.imageItem().getHistogram(perChannel=True)
if ch[0] is None:
return
for i in range(1, 5):
if len(ch) >= i:
h = ch[i-1]
self.plots[i].setVisible(True)
self.plots[i].setData(*h)
if autoLevel:
mn = h[0][0]
mx = h[0][-1]
self.region[i].setRegion([mn, mx])
else:
# hide channels not present in image data
self.plots[i].setVisible(False)
# make sure we are displaying the correct number of channels
self._showRegions()
def getLevels(self):
"""Return the min and max levels.
For rgba mode, this returns a list of the levels for each channel.
"""
if self.levelMode == 'mono':
return self.region.getRegion()
else:
nch = self.imageItem().channels()
if nch is None:
nch = 3
return [r.getRegion() for r in self.regions[1:nch+1]]
def setLevels(self, min=None, max=None, rgba=None):
"""Set the min/max (bright and dark) levels.
Arguments may be *min* and *max* for single-channel data, or
*rgba* = [(rmin, rmax), ...] for multi-channel data.
"""
if self.levelMode == 'mono':
if min is None:
min, max = rgba[0]
assert None not in (min, max)
self.region.setRegion((min, max))
else:
if rgba is None:
raise TypeError("Must specify rgba argument when levelMode != 'mono'.")
for i, levels in enumerate(rgba):
self.regions[i+1].setRegion(levels)
def setLevelMode(self, mode):
""" Set the method of controlling the image levels offered to the user.
Options are 'mono' or 'rgba'.
"""
assert mode in ('mono', 'rgba')
if mode == self.levelMode:
return
oldLevels = self.getLevels()
self.levelMode = mode
self._showRegions()
# do our best to preserve old levels
if mode == 'mono':
levels = np.array(oldLevels).mean(axis=0)
self.setLevels(*levels)
else:
levels = [oldLevels] * 4
self.setLevels(rgba=levels)
# force this because calling self.setLevels might not set the imageItem
# levels if there was no change to the region item
self.imageItem().setLevels(self.getLevels())
self.imageChanged()
self.update()
def _showRegions(self):
for i in range(len(self.regions)):
self.regions[i].setVisible(False)
if self.levelMode == 'rgba':
imax = 4
if self.imageItem() is not None:
# Only show rgb channels if connected image lacks alpha.
nch = self.imageItem().channels()
if nch is None:
nch = 3
xdif = 1.0 / nch
for i in range(1, nch+1):
self.regions[i].setVisible(True)
self.regions[i].setSpan((i-1) * xdif, i * xdif)
self.gradient.hide()
elif self.levelMode == 'mono':
self.regions[0].setVisible(True)
self.gradient.show()
else:
raise ValueError("Unknown level mode %r" % self.levelMode)
def saveState(self):
return {
'gradient': self.gradient.saveState(),
'levels': self.getLevels(),
'mode': self.levelMode,
}
def restoreState(self, state):
self.setLevelMode(state['mode'])
self.gradient.restoreState(state['gradient'])
self.setLevels(*state['levels'])
def setOverlay(self,state=False):
self.overlay = state