QGraphicEffects not working on second thread

[wysota]

i have some heavy image computation on hundreds of pictures

And where does QGraphicsBlurEffect fit into this?

[eric_vi]

because it is part of the different algorithms i use in my offscreen processing. The blurring effect of QGraphicsBlurEffect that i apply on my buffers thru a transform to QPixMap fits well what i need. If i code the blur algorithm myself all work well, that is what i was doing before, but i have more speed with QGraphicsBlurEffect so i want to use it.

[wysota]

If you code the blur effect yourself, you can use OpenCL or texture shaders to get speedup. If you don't want that then you can still use Qt's blurring algorithm - either cut it out of Qt's sourcecode or adjust your code and call the internal function responsible for performing the blur in Qt. QPixmap can only be used in the GUI thread so you should probably focus on transforming QImage instead.