3 standard supports five picture formats: sub- QCIF, QCIF, CIF, 4CIF, and 16CIF. The luminance component of the picture is sampled at these resolutions, while the chrominance components are subsampled by a factor of two in both horizontal and vertical directions. H.263+ is an extension of H.263 which provides new negotiable modes and additional features (ITU-T, 1998; Côté et al., 1999). These features improve compression performance over packet-switched networks and support custom picture size. Recently, a new video codec, H.264/AVC (Advanced Video Coding), has been standardized. The codec has been in use since May 2003 and is intended for coding at very low bitrates. It has been recom- mended by the ITU-T Video Coding Experts Group (VCEG) and the ISO/IEC Moving Picture Experts Group (MPEG) (ISO-TEC, 2003). The codec is reported to have better per- formance than existing codecs, with enhanced compression performance and provision of network-friendly video representation. More literature about H.264 is available from Ghanbari (2003) and Wiegand and colleagues (2003). The Joint Photographic Experts Group (JPEG) standard was developed by the ISO in col- laboration with ITU-T for encoding, transmitting, and decoding still images (Ghanbari, 2003; Wallace, 1991). The JPEG coding scheme compresses still images, including both gray scale and color, using any color space, and can be applied to most image sizes. Compression ratios of up to 15:1 for full-color images are achievable. JPEG specifies lossy and lossless classes of compression and decoding, employing the Discrete Cosine Transform (DCT) and Differ- ential Pulse Code Modulation (DPCM), respectively. Several encoding modes are available with the JPEG lossy compression method: base- line sequential mode, progressive mode, and hierarchical mode (Wallace, 1991). In baseline mode, an image is partitioned into 8 X 8 blocks of pixels. A forward DCT is applied to each 8 X 8 block to generate DCT coefficients, transforming the image from the spatial to the frequency domain