Don't use the constructor that takes an existing buffer. If you use e.g. QImage ( int width, int height, Format format ) it will manage its own memory. Obviously this is sub-optimal if you happen to already have the image data in memory, but it will make resource management much easie
I've an existing buffer in memory.
I can use the QImage ( int width, int height, Format format ) constructor also, but how I can fill the qimage with my buffer and leave the QImage manage its own memory ?!

Ex. setPixel() ???????