The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
In this paper we propose two image watermarking algorithms, which are robust to cropping operation using self-synchronization mechanism. In both algorithms, the watermark sequence is firstly encoded by non-cyclic Low Density Parity Check Codes (LDPC) and then it is embedded into the block-wised Discrete Cosine Transform (DCT) coefficients using the Quantization Index Modulation (QIM) algorithm. In...
In this paper, we analyze audio watermarking methods based on quantization index modulation and low-density parity-check (LDPC) codes. We found that dither modulation (DM) can achieve better performance using half-rate Margulis LDPC code even better than some low-rate codes. Then, we propose a scheme based on LDPC codes and DM with distortion-compensation (DC) property which has a robustness benefit...
A new method for decoding low-density lattice codes is given, wherein the belief-propagation decoder messages are single Gaussian functions. Since the message can be represented by two numbers, a mean and a variance, the complexity of this decoder is lower than previous decoders, which either quantized the mixture, or used a mixture of Gaussians. The computational complexity at the check node is also...
For decoding low-density parity-check (LDPC) codes on discrete memoryless channels, a method to quantize messages and to find message-passing decoding functions for the variable and check nodes is developed. These are used to obtain noise thresholds by density evolution. The message-passing decoding alphabet is restricted to be discrete with a fixed maximum alphabet size. Discrete quantization is...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.