Successive frames in a video sequence are highly correlated and they can be effectively represented by describing the inter-frame motions. Most conventional motion compensations require many calculations in the pixel ...
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ISBN:
(纸本)0780362985
Successive frames in a video sequence are highly correlated and they can be effectively represented by describing the inter-frame motions. Most conventional motion compensations require many calculations in the pixel domain, and this makes a difficulty in real time encoding. In this paper, we propose a simple and fast motion compensation that leads to a fast encoding. In our proposed method, all motions are described in the wavelet transform domain. The subtree coefficients that belong to a de coefficient are assumed to translate in the same direction and thus they can be represented by one motion vector (mx, my). Since one wavelet tree unit-translation in n-scale decomposition corresponds to a 2(n) pixel displacement in the pixel domain, we can describe the inter-frame motions with low cost and complexity. The error frame from the prediction is encoded by a flexible zerotree coding scheme(FZW) that permits exact bit-rate or quality controls.
The embedded zero-tree wavelet (EZW) coding algorithm which was first introduced by Shapiro is a very effective technique for low bit-rate still image compression. In the current study, we propose a novel algorithm to...
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ISBN:
(纸本)9781424417513
The embedded zero-tree wavelet (EZW) coding algorithm which was first introduced by Shapiro is a very effective technique for low bit-rate still image compression. In the current study, we propose a novel algorithm to improve the performance of EZW coding. To reduce the scanning and symbol redundancy of the existing EZW the proposed method is based on the use of six symbols instead of four. The purpose of this technique is to avoid the encoding of the children of each significant coefficient on the condition that it has no significant descendant. In addition, It is shown that this new technique is not only fast and computationally efficient, but also retains the property of embeddedness and obtains higher coding efficiency when compared with the conventional EZW.
When CCD camera photographs massive images in the air, it is very important to compress and save CCD image timely and validly. This paper designs the CCD image compression and mass storage system. The one part is imag...
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ISBN:
(纸本)0819460583
When CCD camera photographs massive images in the air, it is very important to compress and save CCD image timely and validly. This paper designs the CCD image compression and mass storage system. The one part is image compression: this paper introduces a reduced memory still image compression algorithm based on Listless zerotree coding (LZC). Compared with SPIHT, the approach significantly reduced memory requirement and no reducing the quality of the reconstructed image. The other part is image mass storage: this system uses a kind of special hard disk storage devices that can realize faster data transmission to SCSI (Small Computer System Interface) devices even if it separates oneself from PCs. In the faster data acquisition and storage system, data storage is a key technology. Normal approach is saving the data to mass memories, and then processing and saving the data after complete acquisition. The continuous acquisition time is restricted with the storage capacity in the normal method so that it can't receive the requirement of CCD image storage on many occasions. While its price will be geminate increasing, when we increase the storage capacity. So the approach in this paper is better one to use fast disks on data direct mass storage considering the storage capacity, read/write speed and unit cost. The result of the experiment shows that the system has compressed and saved CCD image validly, so it reached the anticipative purpose.
Wavelet based image compression is getting popular due to its promising compaction properties at low bit-rate. zerotree wavelet image coding scheme efficiently exploits multi-level redundancy presented in transformed ...
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ISBN:
(纸本)9781424441303
Wavelet based image compression is getting popular due to its promising compaction properties at low bit-rate. zerotree wavelet image coding scheme efficiently exploits multi-level redundancy presented in transformed data to minimize coding bit. In this paper, a novel compression algorithm for weather radar data based on zerotree coding is presented. Considering the dependence of radar data, an efficient pre-processing algorithm of the data is given first and the redundancy of the data is efficiently reduced. Then an advanced Embedded zerotree Wavelet encoding algorithm is presented which uses context-based adaptive arithmetic coding to improve its performance. Experimental results show that for weather radar data, the proposed algorithm achieves good PSNR even in very low bit rate.
In this paper, a scalable audio compressing scheme is presented, which is mainly based on an Embedded zerotree Wavelet (EZW) coding technology. Firstly, 29 critical subbands are obtained by splitting
In this paper, a scalable audio compressing scheme is presented, which is mainly based on an Embedded zerotree Wavelet (EZW) coding technology. Firstly, 29 critical subbands are obtained by splitting
In this paper, we combine PC and digital signal processing chips to build up a DSP-based color image processing circuit. In our design, user can set up the structure of the circuit to fit their own requirements. For l...
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In this paper, we combine PC and digital signal processing chips to build up a DSP-based color image processing circuit. In our design, user can set up the structure of the circuit to fit their own requirements. For large image data processing, we integrate DRAM into the circuit design and use memory switch technique to enhance the processing speed. Moreover, when adapting our circuit to the color image compressing applications, we revise the Wavelet Transform and zerotree coding algorithm based on practical considerations. Experimental results show that, under the acceptable quality of human eyes, revised algorithms has higher compression ratio.
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