I am trying to call ippiColorToGray_16s_C3C1R and have a strange results. For typical image in range 0 - 255 (but in 16s) and standard coeffs i get pixels with value below -10000.
Finding the reason, I tried to call this func with different input. e.g. with zero coeffs, with only one non-zero coeff and with only-one-pixel image (1x1)
With zero coeffs, result is 16s min (-32,768, 0 expected) so it makes me think about unsigned result - but in docs it says that Dst type is similar to Src. So, can anyone resolve my doubts? Is it bug or what?
UPD: Works fine if coeffs sum is equal to 1. If it less - as said above