Image Compression Techniques

By: Mayra Caceres & A. Anil Kumar (Supported by DOE)

In transmission applications, such as broadcast television, remote sensing via satellite, aircraft, radar, sonar, teleconferencing, computer communications, facsimile transmission, and multimedia systems, compression techniques are constrained by real time and on-line considerations that limit the size and complexity of the hardware. There are three main reasons why present multimedia systems require that data must be compressed: 1) large storage requirements of multimedia data, 2) relatively slow storage devices that do not allow playing multimedia data (specially video) in real-time, and 3) the present network bandwidth, which does not allow real-time video data transmission.

Wavelet-based compression schemes are relatively new techniques for image compression with excellent results yielding higher compression ratios, as well as applying multiresolution properties to image retrieval and visualization. People working with wavelets think that it should be developed to be a wavelet image compression standard more general than just for fingerprints applications (FBI). Our results based on the comparison between JPEG and Wavelets also confirm that idea. Another aspect is working with moving pictures, which make wavelet methods work for video compression as well.