A dithering pattern that is generated based on a spatial operation is used for a Bit-Depth Extension (BDE) technique for preventing contouring artifacts in an image displayed by a display having a bit-depth that-is less than the bit-depth of the image. The dithering pattern can be based on achromatic visual model or a spatio-chromatic visual model. The dither pattern is formed by shaping a pseudo-random noise signal by an equivalent noise visual model that is based on an array of pixels. Alternatively, the array of pixels is based on an image, or a determinate array of pixels.