Old implementation did
lut[i] = 255 * (count(Y <= i)) / (width * height)
which actually shifts uniform histograms.
From now histogram is equalized as
C = count(Y == min(Y))
lut[i] = 255 * (count(Y <= i) - C) / (width * height - C)
Old implementation did
lut[i] = 255 * (count(Y <= i)) / (width * height)
which actually shifts uniform histograms.
From now histogram is equalized as
C = count(Y == min(Y))
lut[i] = 255 * (count(Y <= i) - C) / (width * height - C)