There are two types of image file compression algorithms: lossless and lossy.
Lossless compression algorithms reduce file size while preserving a perfect copy of the original uncompressed image. Lossless compression generally, but not exclusively, results in larger files than lossy compression. Lossless compression should be used to avoid accumulating stages of re-compression when editing images.
Lossy compression algorithms preserve a representation of the original uncompressed image that may appear to be a perfect copy, but it is not a perfect copy. Oftentimes lossy compression is able to achieve smaller file sizes than lossless compression. Most lossy compression algorithms allow for variable compression that trades image quality for file size.
Read more about this topic: Image File Formats
Famous quotes containing the words image, file and/or compression:
“No man hath any quarrel to me. My remembrance is very free and clear from any image of offence done to any man.”
—William Shakespeare (1564–1616)
“Probably nothing in the experience of the rank and file of workers causes more bitterness and envy than the realization which comes sooner or later to many of them that they are “stuck” and can go no further.”
—Mary Barnett Gilson (1877–?)
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—Samuel Beckett (1906–1989)