Patent ID: 7127079

Claim:
An image processing apparatus operable to embed data into an image, said apparatus comprising: a combining processor operable to form said data into a transform domain representation providing a plurality of sub-bands divided by spatial frequency components, said transform domain representation being the discrete wavelet transform, each of said sub-bands comprising wavelet coefficients and, in combination with a transform processor, to combine said data with said image in a transform domain form, said transform processor generating a transform domain form of said image, said data being combined with said image by said combining processor in said transform domain, said transform processor generating a spatial domain representation of said combined image and data, wherein said data is formed into said sub-bands representing said data in a scan direction, with an effect that said data is embedded in only a first low vertical, high horizontal spatial frequencies sub-band of the discrete wavelet transform, and only a second high vertical, low horizontal spatial frequencies sub-band of the discrete wavelet transform, said data being embedded into to said first and second sub-bands in a vertical scan direction and a horizontal scan direction respectively, symbols of said data being added to the wavelet coefficients, said scan direction being in the same direction in the sub-band as the direction of the low spatial frequencies of the image.