Abstract: This invention provides a method for compositing a source image and a destination image using a mask image to produce a result image in a digital image processing system. The method is, on a pixel-by-pixel basis, using the mask image to select between the source and destination images: where a black color value for a mask pixel selects the color value of the corresponding pixel of the source image; and a white color value for a mask pixel selects the color value of the corresponding pixel of the destination image; and where an intermediate color value for a mask pixel selects a weighted average between source and destination pixel color values. The calculations of the weighted average color value are done in color space, such as on a color component by color component basis. The result image can be displayed or stored for further use. This method can be described in boolean expression according to the formula:result=((1-mask)*source)+(mask*destination).