Image processing on compressed data for large video databases

Abstract

This paper presents a novel approach to processing encoded video sequences prior to decoding. Scene changes may be easily detected using DCT coefficients in JPEG and MPEG encoded video sequences. In addition, by analyzing the DCT coefficients, regions of interest may be isolated prior to decompression, increasing efficiency of any subsequent image processing steps, such as edge detection. The results are currently used in a video browser, and are part of an ongoing research project in creating large video databases. The procedure is presented in detail and several examples are exhibited.