How to get matrix elements from Image in C#.net?

I am new to Image Processing. I need to apply the Mean Filter for an image, so that needs to get the matrix elements in one pixel from an image.

I am getting a pi开发者_JS百科xel value as 2*2 Matrix (ARGB) like (255,103,103,103). I don't know how to convert the color values (255,103,103,103) to an Integer like 25678 so that I can find the mean value.

Please help me out with the problem.

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int argb = Color.FromArgb(255,103,103,103).ToArgb();