This paper proposes a scheme for self-embedding an image into itself as a means for detecting and locating tamper, and self-recovering. The image is divided into 8×8 blocks and each block is DCT transformed. A sp...This paper proposes a scheme for self-embedding an image into itself as a means for detecting and locating tamper, and self-recovering. The image is divided into 8×8 blocks and each block is DCT transformed. A specified number of DCT coefficients of the low frequencies are quantized and encoded using a fixed number of bits. The number of DCT coefficients and their bit lengths are carefully chosen based on the statistical property of these coefficients, so that the encoding bit-string for each block satisfies the payload of each block and has good self-recovering capability. The information (the bit string) about one block B is inserted into the LSB of another distant block, which is separated from B with an offset. The method for choosing the offset is analyzed. The proposed scheme is secure, and can well resist possible forgery attacks.展开更多
文摘This paper proposes a scheme for self-embedding an image into itself as a means for detecting and locating tamper, and self-recovering. The image is divided into 8×8 blocks and each block is DCT transformed. A specified number of DCT coefficients of the low frequencies are quantized and encoded using a fixed number of bits. The number of DCT coefficients and their bit lengths are carefully chosen based on the statistical property of these coefficients, so that the encoding bit-string for each block satisfies the payload of each block and has good self-recovering capability. The information (the bit string) about one block B is inserted into the LSB of another distant block, which is separated from B with an offset. The method for choosing the offset is analyzed. The proposed scheme is secure, and can well resist possible forgery attacks.
