Abstract: A method for mixing a foreground picture and a background picture having different resolutions. Parts of the foreground picture of which the color complies with a color-key are designated as being transparent. Artifacts which are caused by scaling of a foreground picture which contains transparent parts by conventional means are avoided by mixing the foreground picture and the background picture at an intermediate resolution, which is substantially equal to the least common multiple of the resolution of the foreground picture and the resolution of the background picture. Alternatively, instead of actually scaling the pictures to the intermediate resolution, a phase table can be used, the entries of which prescribe how a background pixel should be combined with a predetermined number of foreground pixels.