The Research Of Steganography Based On JPEG Images

Since the 1990's., Information hiding technology has become a hot interest area. Its principle is embedding secret information in the redundant information of the multimedia digital signal. The characteristic of information hiding is that it not only hides the content of information, but also hides the existence of the hidden information.This paper studied on digital steganography technology based on JPEG image. My research includes the following sections:1. This paper summarized the concepts of information hiding and steganography. It introduced the compression standard of JPEG images. Analyzed the several commonly used steganography algorithm based JPEG images. It simulated of the Jpeg-Jsteg algorithm, QTM algorithm and F4 algorithm. Analyzed there hidden capacity, embedding efficiency and the quality of stego-image.2. This paper proposed a JPEG image steganographic method based on quantization table. The method based on the quantization table which generating by Watson human visual system model (HVS), it changes the quantization table to hide the information in the quantization table directly. This method can be used to hide information alone and also can be used to combine with other methods to achieve better results. Because the images are not changed directly, so the change is hard to be found, and extraction of the embedded information easily. In our study, the hiding information capacity of this method is large, and can not be found easily.3. This paper proposed a novel and high capacity steganographic method based on JPEG compression. JPEG standard divides the image into non-overlapping blocks of 8x8 pixels. Then every block uses the DCT transformation. Our method divided the image into non-overlapping blocks of 16x16 pixels instant of 8x8 pixels. Our method combines with Jpeg-Jsteg algorithm, QTM algorithm and the method which proposed in this paper's chapter 3. In our study, the capacity of this method is larger than other methods, and the quality of the image is still good.