ABSTRACT
Protection of digital images is an essential need in most systems, especially those requiring high security such as biometric, telemedicine and image remote sensing systems. Watermarking is an efficient technique for verifying the reliability of images by asserting their authenticity. It is based on embedding a secret message called a watermark in the original image in an imperceptible way. Preserving high perceptual quality of the watermarked image and high robustness of the embedded watermark are the basic dilemmas in designing any watermarking system. Image characteristics such as texture, colour, and brightness/darkness can help to reach an efficient watermarking solution. The importance of these properties emerged from the principles of Human Visual System (HVS). The Multiple-Criteria Decision Making (MCDM) techniques may be used to solve the imprecision of an image’s characteristics in order to achieve image authentication. This chapter starts by an overview of the MCDM approach, and then presents how the texture problem is analyzed using one of the MCDM methods in order to identify highly textured blocks within a host image to hold the watermark with high imperceptibility and high robustness. Detecting the textured regions of an image is represented as a decision-making problem. An MCDM method is therefore used to obtain the set of highly textured regions for embedding watermarks. Two new image watermarking approaches based on texture features and MCDM are presented. One of them is semi-blind and the other one is blind.
