Color embedding into gray images

We present a reversible method to convert color graphics and pictures to gray images based on mapping colors to low-visibility high-frequency textures. From a monochrome textured image, the decoder can identify the textures and recover the color information. An image is textured by carrying a wavelet transform and replacing band-pass sub-bands by the chrominance images. The low-pass sub-band is the same as that of the luminance signal. The decoder performs a wavelet transform on the received gray image and recovers the chrominance channels. Registration problems are discussed and examples are presented.