For the traditional steganographic method of Jsteg, the emmbedment of secret message is completed by dividing cover-image into nonoverlapping blocks of 8×8 pixels, discrete cosine transform （DCT） transforming, ...For the traditional steganographic method of Jsteg, the emmbedment of secret message is completed by dividing cover-image into nonoverlapping blocks of 8×8 pixels, discrete cosine transform （DCT） transforming, and using the standard 8×8 quantization table to quantize. In this paper, a novel steganographic method based on the JPEG quantization table modification is presented. Instead of dividing cover-image into 8×8 blocks, nonoverlapping blocks of 16×16 pixels is used. Both theoretical anlysis and experiment results show that the new methods has larger steganography capacity and better stego-image quality, compared with the method of Jsteg and Chang＇s展开更多
In the field of economy, there are more and more electronic scanning cash images, which need to be compressed in a higher compression ratio. This paper proposes a specific compression algorithm for cash images. First,...In the field of economy, there are more and more electronic scanning cash images, which need to be compressed in a higher compression ratio. This paper proposes a specific compression algorithm for cash images. First, according to cash image characteristics and standard JPEG （joint photographic experts group） compression, image re-ordering techniques are analyzed, and the method of modifying some blocks into single color blocks is adopted. Then, a suitable quantization table for cash images is obtained. Experimental results show that the method is effective.展开更多
Lossless data hiding can restore the original status of cover media after embedded secret data are extracted. In 2010, Wang et al. proposed a lossless data hiding scheme which hides secret data in vector quantization ...Lossless data hiding can restore the original status of cover media after embedded secret data are extracted. In 2010, Wang et al. proposed a lossless data hiding scheme which hides secret data in vector quantization （VQ） indices, but the encoding strategies adopted by their scheme expand the final codestream. This paper designs four embedding and encoding strategies to improve Wang et aL＇s scheme. The experiment result of the proposed scheme compared with that of the Wang et aL＇s scheme reduces the bit rates of the final codestream by 4.6% and raises the payload by 1.09% on average.展开更多
基金Supported by the National Natural Science Foundation of China(50803016)the Fundamental Research Funds for the Central Universities
文摘For the traditional steganographic method of Jsteg, the emmbedment of secret message is completed by dividing cover-image into nonoverlapping blocks of 8×8 pixels, discrete cosine transform （DCT） transforming, and using the standard 8×8 quantization table to quantize. In this paper, a novel steganographic method based on the JPEG quantization table modification is presented. Instead of dividing cover-image into 8×8 blocks, nonoverlapping blocks of 16×16 pixels is used. Both theoretical anlysis and experiment results show that the new methods has larger steganography capacity and better stego-image quality, compared with the method of Jsteg and Chang＇s
基金supported by the National Natural Science Foundation of China under Grant No. 60703087the Project of Science and Technology Department of Zhejiang Province under Grant No. 2010C31006 and No. 2011C21081
文摘In the field of economy, there are more and more electronic scanning cash images, which need to be compressed in a higher compression ratio. This paper proposes a specific compression algorithm for cash images. First, according to cash image characteristics and standard JPEG （joint photographic experts group） compression, image re-ordering techniques are analyzed, and the method of modifying some blocks into single color blocks is adopted. Then, a suitable quantization table for cash images is obtained. Experimental results show that the method is effective.
基金supported by the National Science Council,Taiwan under Grant No.NSC 99-2221-E-324-040-MY2
文摘Lossless data hiding can restore the original status of cover media after embedded secret data are extracted. In 2010, Wang et al. proposed a lossless data hiding scheme which hides secret data in vector quantization （VQ） indices, but the encoding strategies adopted by their scheme expand the final codestream. This paper designs four embedding and encoding strategies to improve Wang et aL＇s scheme. The experiment result of the proposed scheme compared with that of the Wang et aL＇s scheme reduces the bit rates of the final codestream by 4.6% and raises the payload by 1.09% on average.
