Information Hiding Schemes Based on the Block Segmentation and Modulus Function

• Main Authors: Chun-Ming Chang, 張鈞名
• Other Authors: Tzu-Chuen Lu
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/19985348266097926227

碩士 === 朝陽科技大學 === 資訊管理系碩士班 === 98 === There are plenty of information hiding technologies have been proposed recently, such as the parity bit replacement, the side match pixel value difference and LSB replacement, modulus function and so on. Most of then still can be improved. This thesis proposes two information hiding technologies to enhance the hiding capacity. The first one is based on modulus function. We use grayscale image as cover medium to embed the secret information. The proposed method divides the image into several non-overlapping blocks and uses a G function to calculate the energy of each block. Then, we transform t bits secret information into a secret symbol in the decimal system. If the energy of the block equals to the secret symbol, then we do not modify the pixel. Otherwise, we calculate the quantity of the modification. The quantities of the modification are shared to each pixel of the block to generate the stego pixels. The second method takes a gray image as a standard medium to generate block patterns. The cover image is divided into several blocks. The scheme compares each block with the block patterns to find a most similar pattern and calculate the difference between the block and the pattern. After that, the scheme embeds the information into the difference. The experimental results shows that the proposed method can increase embed capacity and reduce image distortion effectively.