Robust Digital Image Watermarking Technique Based on Histogram Analysis

Watermarking techniques can be classified into two main categories; Spatial and Transformational approaches. They are characterized to rely on descriptive global models through which each technique is formalized and structured using models of Steganography and Encryption.This paper presents a robust digital image watermarking technique that attributes the watermarking process to signal modulation model. It is based on the histogram analysis for maximum intensity value of pixels. First, carrier image is properly segmented into blocks, then the histogram for each block is drawn and the peak frequency of occurrence for intensity moments in the carrier image is identified. Then bit values of the modulating (watermark) image are used to modulate the histogram peaks of the intensity. Experimentation and analysis on the proposed algorithm show that it is not only simpler and easier to implement, but also it is very effective, secure and robust against different kinds of attacks such as noise, resizing and rotation. Therefore one can conclude that it establishes a concrete judgment for ownership decision to approve ownership in copy write and ownership disputes.