Dynamic Histogram Shifting for Reducing Distortion in Image Embedding
In the recent years, lot of researches is taking place in the field of watermarking to establish more efficient reversible techniques. It is because always there is a need to protect the images of sensitive content such as the military or medical data. The existing system such as the Difference Expansion and Expansion Embedding are most commonly used techniques but suffers from undesirable distortion which makes these methods unsuitable or less reliable. A combination of two techniques pixel histogram shifting and dynamic predictive error histogram shifting are introduced as an attempt to improve the quality of the watermarked image.. The image is first classified invariantly to find which area of the image can be watermarked. On classifying the watermark bits are applied by direct histogram shifting or by shifting it dynamically. Two secret images are embedded into the same cover image considering the odd and even columns of the pixel matrix. This method inserts the payload in the textured area and thus reduces the distortion and it also increases the embedding capacity of the cover image.
V. Lavanya, G. Annapoorani