CODEWITHSUNDEEP
pythonpyqtgraph
brechmos
brechmos

Reputation: 1316

pyqtgraph ImageView and color images

I am trying to display an RGB numpy array in an ImageView() (or similar) within a Dock in pyqtgraph.

The general idea is something like this code:

import pyqtgraph as pg
from pyqtgraph.Qt import QtCore, QtGui
import numpy as np

from pyqtgraph.dockarea import Dock, DockArea

class SimDock(Dock):

    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)

        #self.im1 = pg.image()
        self.im1 = pg.ImageView()

        self.im1.setImage(np.random.normal(size=(100, 100, 3)))
        self.addWidget(self.im1, row=0, col=0)

        self.im1.ui.histogram.hide()
        self.im1.ui.menuBtn.hide()
        self.im1.ui.roiBtn.hide()


app = QtGui.QApplication([])
win = QtGui.QMainWindow()
area = DockArea()
win.setCentralWidget(area)
win.resize(1500, 800)
win.setWindowTitle('pyqtgraph example: dockarea')

simdock = SimDock("Similar Images", size=(500, 500))
area.addDock(simdock, 'right')

win.show()

# Start Qt event loop unless running in interactive mode or using pyside.
if __name__ == '__main__':
    import sys
    if (sys.flags.interactive != 1) or not hasattr(QtCore, 'PYQT_VERSION'):
        app.instance().exec_()

However, when I run the one above I get:

ValueError: could not broadcast input array from shape (100,100,3) into shape (100,100)

When I switch the self.im1 to be pg.image instead of pg.ImageView then an RGB image displays in the Dock, but I get a second empty window (which I assume comes from the pg.image()).

Based on this question, ImageView can accept (M, N, 3) RGB data, but I can't seem to get it to display an RGB image in a widget without the second window popping up.

Upvotes: 2

Views: 3442

Answers (1)

brechmos
brechmos

Reputation: 1316

Well, I found one way of doing it that seems reasonable. There is a post that suggests to subclass pg.ImageView in order to auto add a lookup table for the color. So, in the end I have:

class ColorImageView(pg.ImageView):
    """
    Wrapper around the ImageView to create a color lookup
    table automatically as there seem to be issues with displaying
    color images through pg.ImageView.
    """

    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.lut = None

    def updateImage(self, autoHistogramRange=True):
        super().updateImage(autoHistogramRange)
        self.getImageItem().setLookupTable(self.lut)

then the call in my code becomes self.im1 = ColorImageView().

This works for me and seems reasonably simple.

Upvotes: 2

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