pyqtgraph/graphicsItems/HistogramLUTItem.py

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7.3 KiB
Python
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"""
GraphicsWidget displaying an image histogram along with gradient editor. Can be used to adjust the appearance of images.
"""
from pyqtgraph.Qt import QtGui, QtCore
import pyqtgraph.functions as fn
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from .GraphicsWidget import GraphicsWidget
from .ViewBox import *
from .GradientEditorItem import *
from .LinearRegionItem import *
from .PlotDataItem import *
from .AxisItem import *
from .GridItem import *
from pyqtgraph.Point import Point
import pyqtgraph.functions as fn
import numpy as np
import pyqtgraph.debug as debug
__all__ = ['HistogramLUTItem']
class HistogramLUTItem(GraphicsWidget):
"""
This is a graphicsWidget which provides controls for adjusting the display of an image.
Includes:
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- Image histogram
- Movable region over histogram to select black/white levels
- Gradient editor to define color lookup table for single-channel images
"""
sigLookupTableChanged = QtCore.Signal(object)
sigLevelsChanged = QtCore.Signal(object)
sigLevelChangeFinished = QtCore.Signal(object)
def __init__(self, image=None, fillHistogram=True):
"""
If *image* (ImageItem) 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.
By default, the histogram is rendered with a fill. For performance, set *fillHistogram* = False.
"""
GraphicsWidget.__init__(self)
self.lut = None
self.imageItem = None
self.layout = QtGui.QGraphicsGridLayout()
self.setLayout(self.layout)
self.layout.setContentsMargins(1,1,1,1)
self.layout.setSpacing(0)
self.vb = ViewBox()
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.region = LinearRegionItem([0, 1], LinearRegionItem.Horizontal)
self.region.setZValue(1000)
self.vb.addItem(self.region)
self.axis = AxisItem('left', linkView=self.vb, maxTickLength=-10, showValues=False)
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.grid = GridItem()
#self.vb.addItem(self.grid)
self.gradient.sigGradientChanged.connect(self.gradientChanged)
self.region.sigRegionChanged.connect(self.regionChanging)
self.region.sigRegionChangeFinished.connect(self.regionChanged)
self.vb.sigRangeChanged.connect(self.viewRangeChanged)
self.plot = PlotDataItem()
self.plot.rotate(90)
self.fillHistogram(fillHistogram)
self.vb.addItem(self.plot)
self.autoHistogramRange()
if image is not None:
self.setImageItem(image)
#self.setSizePolicy(QtGui.QSizePolicy.Preferred, QtGui.QSizePolicy.Expanding)
def fillHistogram(self, fill=True, level=0.0, color=(100, 100, 200)):
if fill:
self.plot.setFillLevel(level)
self.plot.setFillBrush(color)
else:
self.plot.setFillLevel(None)
#def sizeHint(self, *args):
#return QtCore.QSizeF(115, 200)
def paint(self, p, *args):
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('k', width=3), pen]:
p.setPen(pen)
p.drawLine(p1, gradRect.bottomLeft())
p.drawLine(p2, gradRect.topLeft())
p.drawLine(gradRect.topLeft(), gradRect.topRight())
p.drawLine(gradRect.bottomLeft(), gradRect.bottomRight())
#p.drawRect(self.boundingRect())
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)
#d = mx-mn
#mn -= d*padding
#mx += d*padding
#self.range = [mn,mx]
#self.updateRange()
#self.vb.setMouseEnabled(False, True)
#self.region.setBounds([mn,mx])
def autoHistogramRange(self):
"""Enable auto-scaling on the histogram plot."""
self.vb.enableAutoRange(self.vb.XYAxes)
#self.range = None
#self.updateRange()
#self.vb.setMouseEnabled(False, False)
#def updateRange(self):
#self.vb.autoRange()
#if self.range is not None:
#self.vb.setYRange(*self.range)
#vr = self.vb.viewRect()
#self.region.setBounds([vr.top(), vr.bottom()])
def setImageItem(self, img):
self.imageItem = img
img.sigImageChanged.connect(self.imageChanged)
img.setLookupTable(self.getLookupTable) ## send function pointer, not the result
#self.gradientChanged()
self.regionChanged()
self.imageChanged(autoLevel=True)
#self.vb.autoRange()
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
#if self.imageItem is not None:
#self.imageItem.setLookupTable(self.gradient.getLookupTable(512))
self.sigLookupTableChanged.emit(self)
def getLookupTable(self, img=None, n=None, alpha=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.region.getRegion())
self.sigLevelChangeFinished.emit(self)
#self.update()
def regionChanging(self):
if self.imageItem is not None:
self.imageItem.setLevels(self.region.getRegion())
self.sigLevelsChanged.emit(self)
self.update()
def imageChanged(self, autoLevel=False, autoRange=False):
prof = debug.Profiler('HistogramLUTItem.imageChanged', disabled=True)
h = self.imageItem.getHistogram()
prof.mark('get histogram')
if h[0] is None:
return
self.plot.setData(*h)
prof.mark('set plot')
if autoLevel:
mn = h[0][0]
mx = h[0][-1]
self.region.setRegion([mn, mx])
prof.mark('set region')
prof.finish()
def getLevels(self):
return self.region.getRegion()
def setLevels(self, mn, mx):
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self.region.setRegion([mn, mx])