A fuzzy approach for data hiding in images

Data hiding has received a lot of attention for the duration of the last decade. Recent techniques use this fact that more information can be hidden in the edge areas of the image versus the smooth areas, without the alterations in the image to be visible. In this paper, we present a new method for data hiding in image in which the image quality is improved. It uses fuzzy-based four-pixel differencing and modified least significant bit (LSB) substitution. Secret data are hidden into each pixel by the n-bit modified LSB substitution method; where, n is obtained using a fuzzy system. The average difference value of the four-pixels block is input of the fuzzy system and its output is the number of bits which have to be embedded in each pixel of the block. There is a fuzzy readjustment procedure, in which gray pixels of the block are altered. It guarantees that the numbers of bits generated by fuzzy system before and after embedding are similar, and minimizes the perceptual alterations. Proposed method has more accuracy in detecting the edge areas of image, because used of pixels value difference based on fuzzy that is more sensitive to changes. Our experimental results have shown that the proposed method not only has good embedding capacity; but also improves the image quality.