This is a plugin for Paint.NET that replaces all segments of one image with equally-sized segments of another image.

Store Image to Replace: Stores the first image, which should be replaced.

Store Replacing Image: Stores the second image, which must be the same size as the first and will replace all copies of it.

Tolerance: How much each pixel is allowed to deviate from the image to replace. Used mostly on lossy-formatted images.

Reset: Discards the stored images.

Replace: Replaces all copies of the first image with the second. It may take awhile.