ComputeThreshold_Otsu Bug(?) when applied to already binary images

Hi all.

I discovered that when you apply ippiComputeThreshold_Otsu_8u_C1R to an 8 bit gray image that only contains 0 and 255 (i.e., is already binarized), the resulting Otsu threshold is t = 0.

From my reading of the documentation, I expected that the "lower" of the two Otsu classes would be all values strictly less than the resulting threshold, i.e. the threshold could have been any value between 1 and 255. The value zero results in a uniformly white image after thresholding regardless of the input.

Best,

Daniel