public void AddSubtractRgb()
{
IImage <RGB> bunny = ImageFactory.GenerateRgb(BunnyPath);
IImage <RGB> added = ImageFunctions.Add(bunny, bunny);
IImage <RGB> original = ImageFunctions.Subtract(added, bunny);
// bunny + bunny - bunny == bunny
Assert.IsTrue(ImagesEqual(bunny, original));
}