Efficient Accordion DWT based Video Coding

Among all multimedia applications, transmission of video frames requires large bandwidth and more bytes for storage. To reduce transmission bandwidth and storage memory, video compression is necessary. The proposed technique compresses the video by reducing the spatial, spectral and temporal redundancies of the input video. Considerable amount of redundancy is often present between a set of frames since only a small portion of each frame is involved with any motion that is taking place. It is called temporal redundancy. Accordion is a method that converts the temporal redundancy into the spatial redundancy. Transformation of the video from 3D to 2D that allows exploring the temporal redundancy of the video using 2D transforms and avoiding the computationally demanding motion recompense step. Accordion transformation converts the spatial and temporal correlation of the video signal into a high spatial correlation. This technique transforms each group of pictures(GOP) into one picture with high spatial correlation.The main advantage of applying Discrete Wavelet Transform(DWT) is to achieve high compression while maintain reconstruction quality. Since, the large data block size is considered compared to Accordion-Discrete Cosine Transform (ACC-DCT); there will be less probability of occurrence of the blocking artifact. The compression ratio was found more for those videos having less motion and vice- versa. Many experimental tests have been conducted to prove the technique efficiency especially in high bit rate and with slow motion video. Since motion is low, temporal redundancy is high and it is expected that ACC-DWT becomes efficient