Reversible Watermarking Using Prediction Error Histogram and Blocking

This paper presents a novel method using block-based predictive error histogram for reversible watermarking in spatial domain. This algorithm employs prediction error to embed data into the cover image. A pixel predictor based on Euclidean distance uses four neighboring pixels to predict the current pixel according to Euclidean distance and hides data into the selected pixels with a special predictive error by histogram shifting. Different from the existing histogram shifting schemes, where only one pair of peak points is used in the given image histogram, we divide the image into non-overlapping blocks and provide a pair of peak points for each block to take full advantage of embedding capacity. The set of peak point values will be compressed by arithmetic coding as a part of overhead information. Comparing with the existing spatial domain reversible watermark methods, the proposed method can achieve much better PSNR value at the high embedding rate. Experimental results prove the effectiveness of the proposed watermarking scheme.