Patent ID: 8687014

Claim:
A method of blending a foreground image with a background image, said foreground and background images being arranged in pixels and having color representations defining the color of each pixel, the foreground image having further an N-bit transparency parameter associated with each pixel, the transparency parameters defining an alpha plane representative of a transparency to apply to the foreground image, the method comprising, for each pixel: applying a dithering operation on the alpha plane to convert the N-bit transparency parameter into a one-bit transparency parameter; multiplexing between the foreground image and the background image using the one-bit transparency parameter; converting the one-bit transparency parameter into one of two extreme values of a predetermined range of continuous values; applying a four-pixel interpolation method to the foreground image to create a five level transparency parameter; and multiplexing predetermined fractional mixtures of the foreground image and the background image using the five level transparency parameter.