The reduction of image file size for processing, storage, and transmission. The quality of the image may be affected by the compression techniques used and the level of compression applied. There are two types of compression:
Lossless compression is a process that reduces the storage space needed for an image file without loss of data. If an image has undergone lossless compression, it will be identical to the image before it was compressed.
Lossy compression is another process that reduces the storage space needed for an image file, but it discards information. If an image that has undergone lossy compression is decompressed, it will differ from the image before it was compressed, even though the difference may be difficult for the human eye to detect.
There are both standard and nonstandard compression techniques available. In general, it is better to employ a compression technique that is supported by standards, is nonproprietary, and maintained over time. In selecting a compression technique, it is necessary to consider the attributes of the original. Some compression techniques are designed to compress text, others are designed to compress pictures.
