What is the mathematical expression for green channel extraction?

Hi, I know that the green channel of a colour image can be extracted by the command green_img=input_img(:,:,2); Can this operation be represented mathematically in any way? What is the process happening in this extraction?

Answer 1

[Image Analyst]

Not really. It is what it is. At least if it's taken from a camera snapshot. Of course you can create/synthesize an image with a green channel created from a specific formula if you want.

Answer 2

[Walter Roberson]

How remarkably odd. Two different people who were active 4 years ago and not since, on the same day post the same question, one that we have never had posted before...

My answer to you, "N", is the same as my answer to "x":

If you need to do it by mathematical formula, then you can use a Projection Matrix

[r, c, p] = size(YourRGBArray);
GreenPlane = reshape(reshape(YourRGBArray,[], 3) * [0; 1; 0], r, c);

I do not recommend this for practical use; matrix indexing is faster and clearer.