Robust watermarking algorithm for medical images based on log-polar transform

Abstract In the information age, network security has gradually become a potentially huge problem, especially in medical field, it is essential to ensure accuracy and safety of images, patient needs be included with minimal change. Combined log-polar transform (LPT) discrete cosine (DCT), novel robust watermarking algorithm for proposed. It realized lossless embedding into images. process feature extraction watermark embedding, proposed reflects characteristics LPT, scale invariance rotation invariance, retains advantages DCT's ability resist conventional attacks robustness. As adopts zero-watermarking technology, solves defects caused by traditional technology modify original image data guaranteed quality The good experimental results show effectiveness this algorithm.