Wavelet packet decomposition

About: Wavelet packet decomposition is a research topic. Over the lifetime, 21977 publications have been published within this topic receiving 395949 citations.

Reversible Data Hiding Based on Histogram Shifting Using Difference Integer Wavelet Coefficients

Abstract: Reversible data hiding, which can restore the original image from the marked image after extraction of hidden message, has drawn more attention recently. This paper proposed a reversible data hiding algorithm based on histogram shifting using difference integer wavelet coefficients. In the proposed algorithm, each difference integer wavelet coefficient is generated between two adjacent integer wavelet coefficients in each sub-band. We use the peak point in the histogram of difference integer wavelet coefficients in each sub-band to hide data in the integer wavelet coefficients. Experimental results demonstrate that the proposed algorithm has high embedding capacity with low distortion.

Regularization of optical flow with M-band wavelet transform

Abstract: The optical flow is an important tool for problems arising in the analysis of image sequences. Flow fields generated by various existing solving techniques are often noisy and partially incorrect, especially near occlusions or motion boundaries. Therefore, the additional information on the scene gained from a sequence of images is usually worse. In this paper, discrete wavelet transform has been adopted in order to enhance the reliability of optical flow estimation. A generalization of the well-known dyadic orthonormal wavelets to the case of the dilation scale factor M > 2 with N vanishing moments has been used, and it has proved to be a useful regularizing tool. The advantages in the computations have been shown by experimental results performed on real image sequences.

Systematic design of architectures for M-ary tree-structured filter banks

Abstract: This paper presents an approach for systematically synthesizing VLSI architectures for M-ary tree-structured filter banks which are constructed from a prototype M-channel FIR filter bank. The resulting synchronous architecture is single-rate, i.e., the architecture uses a single clock even though it implements a multirate algorithm. We derive folding equations and use retiming for folding multirate systems to synthesize the control circuitry. A scheduling algorithm is presented which retimes the multirate filter bank to keep the memory requirements of the architecture low. Our approach can be used to design architectures for a wide variety of applications of full and pruned tree-structured filter banks including subband decompositions, discrete wavelet transforms, and computation of wavelet packet bases.

Permuting and lifting wavelet coding for structured 3-D geometry data with expanded nodes

Abstract: One promising method for coding 3-D geometry data is based on the structure processing of a 3-D model on triangle lattice planes, while maintaining connectivity. In the structuring process, each vertex may be assigned to several nodes on the triangular lattice planes. One of the nodes to which a vertex is assigned is selected as a representative node and the others are called expanded nodes. Only geometry data of the vertices at the representative nodes are required for reconstructing the 3-D model. The geometry data at the representative nodes are often separated by expanded nodes on the triangular lattice plane. In this paper we apply a lifting wavelet transform with the permuting process for an expanded node at even locations and the neighboring representative node to reduce the correlations among the separated coordinate values in the lower frequency band. Experimental results for the 3-D model with complex connectivity show the proposed scheme gives better coding performance compared to the usual schemes.

A Translation-Invariant Wavelet Denoising Method Based on Improved Threshold

Abstract: By analyzing the soft threshold and hard threshold,a translation-invariant wavelet denoising method based on improved-threshold is proposed.In order to remove the interference between discontinuous points,the original signal is shifted circulatingly and repeatedly,and then the shifted signals are decomposed by wavelet separately.Afterwards, using the improved threshold quantization algorithm,the wavelet coefficients are estimated by processing the power of the wavelet coefficients and the power of the threshold,and then the signal is reconstructed.The reconstructed signals are shifted reversely,and then the denoised signal is obtained by averaging the reversely-shifted signals.Experimental results of the sEMG(surface electromyography) show that comparing with the traditional threshold methods,this method improves the SNR(signal noise ratio) and reduces the mean square error.