| 英文摘要 |
AS the result of the IT evolution, there are more network applications and demands, particularly for multimedia. Nevertheless, those digital contents may increase the need for storage capacity and network bandwidth. Consequently, data compression is an essential and significant principle for those digital contents because of the smaller data capacity. In general, Image compression schemes can be classified as lossy or lossless. Lossy compression models lower redundancy and irrelevancy through a series of transform in frequency domain to reconstruct the image with the minimum errors. Redundancy reduction eliminates duplication signals, and irrelevancy reduction abates visually insignificant signals. Several lossy compressions, such as JPEG and JPEG2000, have been adopted. Lossless compressions, such as PNG and JPEG-LS, reconstruct the compressed images identically. |