Joint Image Watermarking, Compression and Encryption Based on Compressed Sensing and Entropy Coding

Abstract

Image usage over the internet becomes more and more important each day. Over 3 billion images are shared each day over the internet which raise a concern about how to protect images copyrights? Or how to utilize image sharing experience? This paper proposes a new robust image watermarking algorithm based on compressed sensing (CS) and quantization index modulation (QIM) watermark embedding. The algorithm capitalizes on the CS to compress and encrypt images jointly with Entropy Coding, Arnold Cat Map, Pseudo-random numbers and Advanced Encryption Standard (AES). Our proposed algorithm works under the JPEG standard umbrella. Watermark embedding is done in 3 different locations inside the image using QIM. Those locations differ with each 8-by-8 image block. Choosing which combination of coefficients to be used in QIM watermark embedding depends on selecting a combination from combinations table, which is generated at the same time with projection matrices using a 10-digits Pseudorandom number secret key SK 1. After quantization phase, the algorithm shuffles image blocks using Arnold's Cat Map with a 10-digits Pseudo-random number secret key SK 2 , followed by a unique method for splitting every 8x8 block into two unequal parts. Part number one will act as the host for two QIM watermarks then goes through encoding phase using Run-Length Encoding (RLE) followed by Huffman Encoding, while part number two goes through sparse watermark embedding followed by a third QIM watermark embedding and compression phase using CS, then Huffman encoder is used to encode this part. The algorithm aims to combine image watermarking, compression and encryption capabilities in one algorithm while balancing how those capabilities works with each other to achieve significant improvement in terms of image watermarking, compression and encryption. 15 different images usually used in image processing benchmarking were used for testing the algorithm capabilities and experiments show that our proposed algorithm achieves robust watermarking jointly with encryption and compression under the JPEG standard framework.