This is really interesting, but I'm sad that they skip over the step "convert to grayscale." There's a ton of ways to convert an image to grayscale, each with their own pros and cons.
How do you weight each channel? Do you convert to HSL and just use L? Do you instead use Lab? HSV? Do you do a global or local algorithm? So many questions!
How do you weight each channel? Do you convert to HSL and just use L? Do you instead use Lab? HSV? Do you do a global or local algorithm? So many questions!