Camera image pixel structure origin
It looks like that is a color camera with the Bayer pattern, and the color camera data is directly used as grayscale data, as if it was coming from a grayscale camera. If it is a color camera, the color camera data should be de-Bayerized first (and smoothed etc processing) to get color RGB data pixels as usual, and then the RGB data can be converted to grayscale if grayscale is needed.