A STEGANOGRAPHIC TECHNIQUE FOR COLOR IMAGES USEVGINDEX REPLACEMENT AND PRINCIPAL COMPONENT ANALYSIS

摘要

In this paper, we propose a steganographic method for embedding binary data into indexed-color images without considering its robustness. The objective is to conceal secret data while retaining the quality of the stego-image. The main idea is to replace, only if necessary, the color index of the pixel with the index to another similar color properly selected from the palette. We measure the similarity of different palette colors in terms of their Euclidean distances in the RGB color space. To enhance the speed of searching for a suitable replacement, principal component analysis (PCA) is applied to reorder the palette. Security of our scheme is achieved by employing a pseudo-random scheme to generate the traversing order.