ippiCompareEqualEps with Ipp8u?

[minne]

I want to compare two Ipp8u-images using a function like ippiCompareEqualEps. However, ippiCompareEqualEps is only defined for floating point values only. Of course, I can loop over the image pixels myself, and compare them by hand, but I have the very strong feeling that this might be even slower than converting the image to 32f and using ippiCompareEqualEps.

And now this is the thing: I need to do this comparison very very very often, so I need it to be as fast as possible. What is the fastest way to do this? And why is ippiCompareEqualEps not defined for integer pixel values?

[minne]

I did a small speed test, and indeed comparing Ipp32f using ippiCompareEqualEps is approximately 50% faster than comparing Ipp8u by looping over the image.

Nobody any idea how to speed up the comparison of Ipp8u values?