  In this paper, an efficient fragile blind quad watermarking scheme for image
tamper detection and recovery based on lifting wavelet transform and genetic
algorithm is proposed. TRLG generates four compact digests with super quality
based on lifting wavelet transform and halftoning technique by distinguishing
the types of image blocks. In other words, for each 2*2 non-overlap blocks,
four chances for recovering destroyed blocks are considered. A special
parameter estimation technique based on genetic algorithm is performed to
improve and optimize the quality of digests and watermarked image. Furthermore,
CCS map is used to determine the mapping block for embedding information,
encrypting and confusing the embedded information. In order to improve the
recovery rate, Mirror-aside and Partner-block are proposed. The experiments
that have been conducted to evaluate the performance of TRLG proved the
superiority in terms of quality of the watermarked and recovered image, tamper
localization and security compared with state-of-the-art methods. The results
indicate that the PSNR and SSIM of the watermarked image are about 46 dB and
approximately one, respectively. Also, the mean of PSNR and SSIM of several
recovered images which has been destroyed about 90% is reached to 24 dB and
0.86, respectively.
