Camera image pixel structure origin I am using machine vision for industry task with opencv. I have images from a camera monitoring the process. The detailed look at the small part of the image follows: 

Enlarged: 

In the detail, it is possible to see pixel chessboard-like pixel structure. I can get rid of it in many ways (any kind of blur or averaging will do the trick). However, I would like to know where this structure origins. My ideas:


camera use colors by default - can the grayscale setting use the RGB sensors in the way that cause this?
could this be produced by compression or storing of the images? I have no information about how it is done - but the images are in PNG format when I get them.


As I said, I can homogenize the image, but I wonder, maybe there is something fundamentally wrong what we do and that should be fixed.
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.