Color image text watermarking using wavelet transform and error-correcting code

A text watermark algorithm using wavelet transform and error-correcting code for color image is presented. First, we decompose the blue channel of the original color image to three levels using Daubechies´ wavelets, which are well suited to deal with general-purpose images. Then the error-correcting encoded text watermark is embedded by modifying the middle-frequency range of wavelet coefficients under the indication of the wavelet coefficient relation matrix (WCRM), which is obtained by comparing coefficients of each resolution layer. The recovering of the watermark does not require the original image. Experimental results show that the algorithm is robust to some image processing operations and JPEG lossy compression.