A mechanism and process for feathering a first image and a second image in a composite image includes defining an original matte image. A portion of the original matte image is box filtered horizontally and vertically to generate an intermediate matte image. At least a portion of the intermediate matte image is box filtered horizontally and vertically to generate a processed matte image. An edge biasing function is applied to the processed matte image. Edge biasing includes further modifying pixel values on an edge by changing the contrast and brightness of the matte image. A composite image including the first image and the second image is then generated after applying the edge biasing function to the box-filtered processed matte image.