public sealed class Subtract : BaseInPlaceFilter2

The subtract filter takes two images (source and overlay images) of the same size and pixel format and produces an image, where each pixel equals to the difference value of corresponding pixels from provided images (if difference is less than minimum allowed value, 0, then it is truncated to that minimum value).

The filter accepts 8 and 16 bpp grayscale images and 24, 32, 48 and 64 bpp color images for processing.

Sample usage:

CopyC#

// create filter
Subtract filter = new Subtract( overlayImage );
// apply the filter
Bitmap resultImage = filter.Apply( sourceImage );

Source image:

Overlay image:

Result image:

System..::.Object
  AForge.Imaging.Filters..::.BaseInPlaceFilter
    AForge.Imaging.Filters..::.BaseInPlaceFilter2
      AForge.Imaging.Filters..::.Subtract