Re: [PyQt4]C array to QImage
Have you tried the QImage(sip.voidptr data, int width, int height, Format format) constructor? The first argument, data, should be just what you're looking for: it's a void * pointing to the beginning of your data array. Be sure to set Format correctly, so that QImage knows how to interpret your data array.
As for faster image computations: check out the Python Image Library (PIL). It's a powerful (and fast) module for image creation / manipulation. You should get a nice performance boost if you can use PIL for some of your work.