To ensure the integrity and security of medical images,a block based semi fragile watermarking medical image algorithm based on singular value decomposition is proposed,which has two functions:locating image tampered areas and image self recovery.This algorithm di-vides the image by 4 × Divide the watermark into blocks of 4 sizes and divide the embedding position into two types:block authentication bit and self recovery reset.The block authentication bit is used to authenticate each block,ensuring that it can be recognized when tampered with;Self recovery reset is used to achieve self recovery of images after being tampered with.Generate block authentication bits through singu-lar value decomposition for block partitioning,while dividing the block into 2 x Calculate the average value of 5MSB for blocks of 2 to generate self recovery reset.The simulation experiment results show that the PSNR index of the proposed algorithm is above 50 dB,and for most tamper-ing attacks,the Rfa and Rfd are close to 0,and the PSNR index of the self recovered image is above 30 dB.The proposed algorithm has good transparency,can accurately detect most tampering attacks,and has good self recovering image quality.
维普
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