A data compression process that makes subsequent complete recovery of the original data impossible. This approach is commonly used for still- or motion-images where the recovered image must only be subjectively acceptable. Algorithm examples include JPEG, MPEG1, MPEG2, MPEG4, H.261 and H.263. Note that lossy compression can provide significantly greater compression than lossless compression techniques. See also Cosine Transform.
Lossy compression is a compression scheme that emphasizes producing a small picture file, even at the cost of picture quality. Lossy compression can produce smaller picture files than lossless compression; however, when you uncompress the picture, some of the original picture data is lost and cannot be recovered.
Method of file compression that causes an image to lose it's quality, and is not capable of returning it back to it's original quality.