A Watermarking Technique for Color Images using Tone Insertion

K. Gopalan (USA)


Image communication, Image processing, Oblivious retrieval, Watermarking


An oblivious technique for embedding imperceptible watermark information on a color image is described. By converting the color image to a one-dimensional signal in red, green, or blue, audibly masked frequencies in the one dimensional signal are determined for each segment or block. Embedding of predetermined watermark data at preselected image blocks is carried out by modifying the spectral power at a pair of commonly occurring ‘audibly’ masked frequencies. The proposed technique is simple to implement based on the psychoacoustical masking property, and it yields an imperceptibly watermarked image in each of the primary colors. Also, the watermark is robust to noise at low levels. Additionally, oblivious retrieval of the hidden watermark renders the technique useful for covert communication.

Important Links:

Go Back