Manipulate color of QImage - QT

Question

I have one generic icon image, which has an alpha. Lets say a black sphere placed on an square button, with transparancy. Now I would like to change the color of the icon on the fly, without having several image of sphere_black.png, sphere_red.png etc etc. Is there a way to colorize the pixmap, respecting the alpha and change HSV on that pixel, for all in the map?

I have something like this, but stuck:

img = QtGui.QImage(kwargs['icon_path']
pxmap = QtGui.QPixmap(img)
for x in range(img.width()):
    for y in range(img.height()):
         print img.pixel(1, 1), '###'
         # ???? #

Any help is appreciated!

Answer 1

QGraphicsColorizeEffect might be what you are looking for. Sadly the QGraphicsEffect class is made to be used with the graphics view framework, it can't easily be applied to a QImage . However there are workarounds for that, as this discussion shows.

The implementation of the effect in QPixmapColorizeFilter::draw() shows how the colourization is done: A coloured rect (with the color having the alpha set to something else than fully opaque) is drawn over the image with QPainter::fillRect() , with an appropriate composition mode set.