The rapid development of data communication in modern era demands secure exchange of information. Steganography is an established method for hiding secret data from an unauthorized access into a cover object in such a...The rapid development of data communication in modern era demands secure exchange of information. Steganography is an established method for hiding secret data from an unauthorized access into a cover object in such a way that it is invisible to human eyes. The cover object can be image, text, audio,or video. This paper proposes a secure steganography algorithm that hides a bitstream of the secret text into the least significant bits（LSBs） of the approximation coefficients of the integer wavelet transform（IWT） of grayscale images as well as each component of color images to form stego-images. The embedding and extracting phases of the proposed steganography algorithms are performed using the MATLAB software. Invisibility, payload capacity, and security in terms of peak signal to noise ratio（PSNR） and robustness are the key challenges to steganography. The statistical distortion between the cover images and the stego-images is measured by using the mean square error（MSE） and the PSNR, while the degree of closeness between them is evaluated using the normalized cross correlation（NCC）. The experimental results show that, the proposed algorithms can hide the secret text with a large payload capacity with a high level of security and a higher invisibility. Furthermore, the proposed technique is computationally efficient and better results for both PSNR and NCC are achieved compared with the previous algorithms.展开更多
提出了基于整数小波变换和多级树集合分裂SPIHT(Set Partitioned in Hierarchical Tree)编码的电力系统录波数据压缩方法。首先对故障录波数据进行整数小波变换,再对变换后系数量化,然后进行一维SPIHT编码形成嵌入式码流,便于系统根据...提出了基于整数小波变换和多级树集合分裂SPIHT(Set Partitioned in Hierarchical Tree)编码的电力系统录波数据压缩方法。首先对故障录波数据进行整数小波变换,再对变换后系数量化,然后进行一维SPIHT编码形成嵌入式码流,便于系统根据通讯线路的负荷情况灵活控制传输码率。整数小波变换运算速度快,节约内存,易于DSP实现。SPIHT编码方法形成的码流易于实现可变码率。仿真结果验证了该方法的有效性。展开更多
文摘The rapid development of data communication in modern era demands secure exchange of information. Steganography is an established method for hiding secret data from an unauthorized access into a cover object in such a way that it is invisible to human eyes. The cover object can be image, text, audio,or video. This paper proposes a secure steganography algorithm that hides a bitstream of the secret text into the least significant bits（LSBs） of the approximation coefficients of the integer wavelet transform（IWT） of grayscale images as well as each component of color images to form stego-images. The embedding and extracting phases of the proposed steganography algorithms are performed using the MATLAB software. Invisibility, payload capacity, and security in terms of peak signal to noise ratio（PSNR） and robustness are the key challenges to steganography. The statistical distortion between the cover images and the stego-images is measured by using the mean square error（MSE） and the PSNR, while the degree of closeness between them is evaluated using the normalized cross correlation（NCC）. The experimental results show that, the proposed algorithms can hide the secret text with a large payload capacity with a high level of security and a higher invisibility. Furthermore, the proposed technique is computationally efficient and better results for both PSNR and NCC are achieved compared with the previous algorithms.
文摘提出了基于整数小波变换和多级树集合分裂SPIHT(Set Partitioned in Hierarchical Tree)编码的电力系统录波数据压缩方法。首先对故障录波数据进行整数小波变换,再对变换后系数量化,然后进行一维SPIHT编码形成嵌入式码流,便于系统根据通讯线路的负荷情况灵活控制传输码率。整数小波变换运算速度快,节约内存,易于DSP实现。SPIHT编码方法形成的码流易于实现可变码率。仿真结果验证了该方法的有效性。
