Patent ID: 7742619

Claim:
A method for embedding a binary watermark image into a gray scale host image comprising the steps of: discrete wavelet transforming the host image; discrete binary wavelet transforming the watermark image; for each sub-band subb selected from the set of LL, LH, HL and HH of a first predetermined transform level of the host image and a second predetermined transform level to the watermark image thresholding and binarizing data elements of the corresponding sub-band of the discrete wavelet transformed host image, comparing sequencies of thresholded and binarized data elements of the discrete wavelet transformed host image with sequencies of the discrete wavelet transformed watermark image to form a watermarking sequency mask, forming watermarked wavelet domain data by combining data elements of the corresponding sub-band of the discrete wavelet transformed host image with data elements of the corresponding sub-band of the wavelet transformed watermark image as filtered by the watermarking mask, and inverse discrete transforming the watermarked wavelet domain data thereby forming a watermarked host image.