Research On Three Dimession Video Compression Based Discrete Cosine Transform And Wavelet Transform

Digital video coding is one of the key technologies of multimedia communication The relationship not only exsits intrafiame , but also exsits interframe of video sequences . This thesis study low bitrate video coding through three dimension space: the video sequence regarded as three dimensional image is transformed by three dimensional diecrete cosine transform (3DDCT) or three dimensional wavelet transform(3DWT), then coded in the transformed space. The main work includes:1. The 3DDCT algorithm is deeply studied in this thesis . Combined the characteristic of XYZ coding, a video coding program based on part 3DDCT algorithm is proposed, which can raise code and decode efficiency by reducing the caculation of transform.2. The quantize policy of XYZ video coding is researched . Combined the visual characteristic of human eye, a new quantization matrix on XYZ video coding is given through evolutionary algorithms. The simulation results show that this method can give high compression ratio and good reconstruct picture qanlity.3. The code policy RLE+Huffman using in the XYZ video coding is still the policy based on 2DDCT, which is not suited to XYZ coding based on 3DDCT. A new code policy is proposed in this thesis which is more suitable for XYZ coding. Experiment results show this new method has higher performance than previous ones.4. The XYZ compression efficiency decrease in case of video sequence with violent motion. To counter video sequences with violent motion, a new video coding scheme based on three dimensional cosine transformation with motion compensation is presented. Every eight oringal sequence pictures are compensated through motion estimation, and then use XYZ method to code. The simulations demonstrate that this method is very efficient.5. Digital video sequence can be regarded as sampling of analogue video signal, sampling too intensive can make the intraframe relationship higher, and sampling too sparse can make the intraframe relationship lower. Based on sampling theory, a variant rate XYZ video coding method is proposed in this thesis, which can improve the coding efficiency.6. Zerotree coding is very efficient in multiresolution image coding. With reorganize the...