# Revision history [back]

the Y stands for the grayscale pixel value, not for alpha (which is irrelevant for computer vision, and thus just gets discarded)

the formula is actually a weighted sum, gray = (0.299 * red) + (0.587 * green) + (0.114 * blue).

maybe it gets more obvious, if you just add up the factors: 0.299 + 0.587 + 0.114 = 1

the Y stands for the grayscale pixel value, not for alpha (which is irrelevant for computer vision, and thus just gets discarded)

the formula is actually a weighted sum,

gray = (0.299 * red) + (0.587 * green) + (0.114 * blue).

maybe it gets more obvious, if you just add up the factors: factors:

0.299 + 0.587 + 0.114 = 1