python - PIL Image to QPixmap conversion issue

Question

I've been struggling with this challenge for the best of today, I've managed to get a good point using previous posts and other resources.

I'm trying to convert a PIL.Image to a QPixmap so that I can display using a QgraphicsScene on my PyQT GUI. However when the picture is displayed the colours have changed?? Has anyone ever experienced this issue?

The code I use for this is as below.

self.graphicsScene.clear()
im = Image.open('Penguins.jpg')
im = im.convert("RGBA")
data = im.tobytes("raw","RGBA")
qim = QtGui.QImage(data, im.size[0], im.size[1], QtGui.QImage.Format_ARGB32)
pix = QtGui.QPixmap.fromImage(qim)
self.graphicsScene.addPixmap(pix)
self.graphicsView.fitInView(QtCore.QRectF(0,0,im.size[0], im.size[1]), QtCore.Qt.KeepAspectRatio)
self.graphicsScene.update()

Im on windows 7 64bit, using python 3.4 with PyQt4 and pillow 3.1.0. The results im getting can be seen below.

Original picture

Picture displayed in GUI

Thanks in advance :).

Answer 1

In your PIL image the last band is the alpha channel, whereas in the Qt image the alpha channels is the first (RGBA vs. ARGB). There may be ways of permuting the bands but the easiest way seems to use the ImageQt class.

from PIL.ImageQt import ImageQt
qim = ImageQt(im)
pix = QtGui.QPixmap.fromImage(qim)