Finding the smallest RGB value?

Question

Python

There is a black and white image, with various shades of gray. There is also an array with decoded RGB data for each pixel. Actually, a question. How to find the blackest pixel and the lightest one from an array?

Answer 1

A black and white image has two colors - black and white.
A grayscale image has one channel.
If you have three channels (RBG) - then this is a full-color image.
The brightness (or luminosity) of a point can be calculated using one of the formulas, depending on the color model:
L = 0.2126 * R + 0.7152 * G + 0.0722 * B
L = 0.299 * R + 0.587 * G + 0.114 * B
L = sqrt(0.299 * R * R + 0.587 * G * G + 0.114 * B * B)