Compression Technique for Multimedia

Abstract

Multimedia system contains different types of data like text, image, audio, video etc. It requires the large storage space and available bandwidth of network does not allowed to transmit the real time multimedia data. For this reason compression of multimedia data is necessary.

The thesis work describes the implementation of 3D-DCT (Three Dimensional Discrete Cosine Transform) video compression technique. It describes the implementation of an Adaptive 3D-DCT compression algorithm. The work required pre-requisite study of available compression standards for multimedia. These standards are based on the 2D-DCT. The algorithm has main three steps, 3D-DCT transform, Quantization and last Entropy encoding. In decompression all the three steps are perform in reverse order. In 3D-DCT compression introduced the quality factor, which will decide the quantization volume vale and quality of the decompressed video. In An adaptive 3D-DCT compression, size of the cube for 3D-DCT transformation and the quantization volume is determined dynamically on the basis of level of motion. The encoder and decoder are written in Matlab tool. An implementation adaptive 3D-DCT compression technique is works well for low motion video and maintaining the quality of the decompressed video but still not giving the high compression ratio. An implementation of 3D-DCT video compression results in the value of the quality factor should be within the range 1-25, beyond that the quality of the decompressed video is not be acceptable.