Tang Xianghong

A watermarking algorithm based on the SVD and Hadamard transform

Digital watermarking is deemed as a novel technique for copyright of digital products and has aroused extensive interest in recent years. Based on the properties of the Hadamard transform and the singular value decomposition (SVD), this paper proposes a novel watermarking algorithm, the experimental results showing that the watermarking algorithm has good transparency and robustness, especially against the geometrical operations and JPEG lossy compression.

A digital watermarking scheme based on DWT and vector transform

This paper proposes a binary image digital watermarking scheme based on the combination of discrete wavelet transform (DWT) and vector transform (VT). Experimental results show that this scheme keeps the image quality rather good and has better robustness to common signal processing operations such as adding noise, filtering and JPEG lossy compression.

An Image Compressing Algorithm Based on Classified Blocks with BP Neural Networks

This paper expounds the principle of BP neural network with applications to image compression and the neural network models. Then an image compressing algorithm based on improved BP network is developed. The blocks of original image are classified into three classes: background blocks, object blocks and edge blocks, considering the features of intensity change and visual discrimination. The BP algorithm is also improved for a better convergence effect and the simulation results indicate that the compression rate and the quality of reconstructed image is effectively improved.

A digital audio watermark embedding algorithm with WT and CCT

This paper propose an audio digital watermarking algorithm based on the wavelet transform (WT) and the complex cepstrum transform (CCT). The algorithm realized to embed a binary image watermark into the audio signal and improved the imperceptibility of watermarks. Experimental results show that this algorithm has a better robustness against common signal processing such as noise, filtering, resampling and lossy compression.

Watermarking for the digital images based on model of human perception

As an effective method to provide copyright protection for digital media, digital watermarking has drawn extensive attention recently. The paper proposes a scheme of digital watermarking based on the modulation transfer function (MTF) of the human visual system(HVS). The experimental results demonstrate its better unification between the watermarking robustness and watermarking invisibility, the watermarking with the proposed scheme is robust against noise interference and commonly used image technique.

Integrity authentication scheme of color video based on the fragile watermarking

The paper presents a scheme for the color video integrity authentication based on fragile watermarking. The RGB color mode is transformed to YST color mode which useing for embedding watermarking into original video. Firstly, the T-component is selected to make DCT by 4×4 blocks. After that, according to the relationship of the quantilzed DCTcoefficients of the frames, the authentication code is created, as watermarking is embeded into the image by modifying the last non-zero DCT coefficient. The video anthentication is carried out without refering to the original video, blind detection can be achieved. The simulation results show that the scheme could keep videos quality and also can detect the tamper and attack on original video.

Zero-Watermark Scheme Based on Audio's Statistical Character

a new zero-watermark algorithm based on audios statistical character is presented. By using the audios statistical character, this paper consults the mean of the approximation coefficients of a one-dimensional signal and constructs the watermark sequence within the zero-watermark scheme. By this way, it is efficient to resolve the required trade-off between the robustness to certain watermark attacks and the imperceptual quality. The experimental results demonstrate that the proposed watermarking algorithm is greatly imperceptible and robust against general malicious attacks.

Study on a multifunction watermarking algorithm

Digital watermarking is deemed as a novel technique for copyright of digital products protecting and has aroused extensive interests in recent years. Based on the properties of the Karhunen-Loeve transform (K-L) and the singular value decomposition (SVD), this paper proposes a novel multifunction watermarking algorithm, the experimental results show that the watermarking algorithm has good transparency and robust, especially against the geometrical operations and JPEG lossy compression.

A direct sequence spread wavelet modulation method

Since wavelet transform has good time frequency property and orthogonality property, wavelet transform be used by communication as modulation waveforms. Based on the characterization of the wavelet modulation (WM) communication system and direct sequence spread spectrum communication (DS), this paper propose a novel wavelet modulation method, which is called direct sequence wavelet modulation (DS-WM). Making use of the joint estimation strategy, the performances of DS-WM are analyzed in three channel models. The experiment results show that the DS-WM has better performance than WM and the joint estimation strategy improves the bit error rate (BER) performance of DS-WM system.

An image inpainting method by structural constraints and sample sparse representation

This paper discusses a way of image inpainting by structural constraints and patch sparse representation. First, we complete the image edge information by polynomial curve fitting to constrain the structure. Second, we redefine the priority in order to repair the structure firstly and present a narrow-band model based on patch sparse representation to complete structural information. Last, we do sparse representation of the shifting patch in place of the target patch to improve the reliability of sparse representation in texture portion. Simulation results show that the proposed method can make higher image quality and maintain the linear structure well.