This example extends the earlier one Pixellate an image and create other effects in C# by adding a new filter that makes a color embossed image without removing most of the color information.
The filter’s kernel is:
1 1 -1 1 1 -1 1 -1 -1
The filter divides the result by 1 and uses no offset so it retains most of the image’s color information. See the earlier post Use image filters to perform edge detection, smoothing, embossing, and more in C# for more information about how kernels work.