34 results about "Wavelet coding" patented technology

Provided is an inter-frame wavelet coding apparatus that can reduce the computation complexity of a decoder by adjusting a decomposition level and a filter length based on the information amount of a frame during wavelet transform and a method therefor. The inter-frame wavelet coding apparatus includes: a Motion Compensated Temporal Filtering (MCTF) unit for computing a motion vectors of a group of pictures (GOP) and filtering the GOP with respect to the temporal axis, to thereby obtain filtered frame; a wavelet transforming unit for performing spatial wavelet transform on the filtered frame and outputting a wavelet coefficient; a quantization unit for quantizing the wavelet coefficient; an entropy coding unit for entropy-coding the motion vector computed in the MCTF unit and the quantized wavelet coefficient, to thereby generate an entropy-coded bit stream; and a wavelet filter managing unit for selecting a decomposition level and a filter length for the wavelet transforming unit based on motion estimation information of the GOP video computed in the MCTF unit, wherein the decomposition level and the filter length are included in the entropy-coded bit stream.

The invention is a new effective and fast method and apparatus for still image compression. The present invention implements an embedded progressive sorting scheme in a quadtree-like structure. In contrast to zerotree-based methods for wavelet coding, the invented embedded quadtree wavelet (EQW) method exploits the inherent spatial self-similarity within individual layers of the multiresolution decomposition hierarchy. This self-similarity offers higher predictability of the data within the same resolution level, and therefore usually provides a higher performance in seeking a compact code. The computation involved in the EQW method is more efficient than in the zerotree wavelet coding, and the produced bitstream is more robust to channel noise. The present invention can be effectively used for object-oriented shape coding or region coding in image and video compression coding systems.

The image encoding uses a base mesh and wavelet coefficients for local modifications of the mesh. Wavelet coefficients are partitioned into disjoint subsets each coded independently. Data permitting location of the wavelet coefficient relative to part of the image is inserted into the data used to reconstruct the image, to allow selective reconstruction of part of the image.

The invention provides a strip wave transform image compression method based on a graphics processor. The method overcomes the defects that in the prior art, the calculation quantity is large and the peak signal to noise ratio of compressed images is low. The method specifically includes the following steps of firstly, inputting an image to be compressed; secondly, conducting wavelet transform; thirdly, conducting Bandelet conversion; fourthly, conducting embedded zerotree wavelet coding and outputting a compressed file; fifthly, inputting the compressed file to be decompressed; sixthly, conducting decoding; seventhly, conducting Bandelet inverse transformation and outputting a reconstructed image. The method can effectively solve the problems that in the prior art, the compression speed is low, image detail characteristics can not be well kept and the peak signal to noise ratio is low, the detail characteristics of the image can be well reserved, the compression speed is increased, and the peak signal to noise ratio of the compressed image is increased.

The invention belongs to the technical field of image communication, and in particular relates to a low-delay image progressive transmission method based on a sliding window BATS code. The purpose of the present invention is to overcome the shortcoming of high time delay of the traditional BATS code, realize reliable image progressive transmission, and improve the QoE of the user to the communication system. Among them, the reduction of time delay and progressive transmission are mainly achieved through the combination of sliding window BATS code and wavelet SPIHT code, and the main idea of ​​the sliding window BATS code based on coding statistics is to improve the ordinary sliding window structure and count the current window The encoded information obtains the compressed data packets that have not participated in the encoding, and continues to encode them in the next window. By increasing the encoding probability, the probability of successful recovery is improved, thereby reducing the code length of the BATS code and the randomness of the encoding. impact on reliability.