Compression effects on color and texture based multimedia indexing and retrieval

This paper presents an evaluation of digital compression effects on content-based multimedia retrieval using color and texture attributes. Subjective evaluation tests that are applied on digital image and video databases using different compression and visual feature extraction techniques have been performed and reported. Simulations show that a satisfactory retrieval performance can be obtained from the compressed databases with 10% compression quality (i.e. 97.6% compression ratio in JPEG). Image retrieval based on HSV color histogram performs better than retrieval based on YUV color histogram in the uncompressed domain, and the other way around in the compressed domain. In general, video retrieval based on color histogram in MPEG-4 compressed databases performs better compared to H.263+ compressed databases. However, retrieval performance from H.263+ compressed databases at lower bit rates is more stable, where it drastically decreases in MPEG-4 compressed databases below 128 Kb/s. Retrieval based on texture features produces more robust performance than retrieval based on color. Subjective tests show that 25% compression quality achieves high compression ratio without loosing significant retrieval performance. The results are particularly relevant to applications in which a mobile device is involved in a multimedia retrieval system.