Robust and Secure Zero-Watermarking Algorithm for Medical Images Based on Harris-SURF-DCT and Chaotic Map

To protect the patient information in medical images, this article proposes a robust watermarking algorithm for images based on Harris-SURF-DCT. First, corners of image are extracted using Harris corner detection algorithm, and then, previously described method describing feature points SURF to generate descriptor matrix. Then, matrix is processed through perceptual hash obtain vector image, which binary with size 32 bits. Secondly, enhance security watermark information, logistic map used encrypt before embedding watermark. Finally, help cryptography knowledge, third party, zero-watermarking technology, can embed without modifying image. When extracting watermark, extract from test original In addition, has strong robustness conventional attacks geometric attacks. Especially under attacks, performs better.