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Lossy Compression

Lossy compression differs from its counterpart, lossless compression, as its name implies—some amount of data may be lost in the process.  Thus, after a compression/decompression cycle, the data set will be modified from the uncompressed original and information may be lost.

One may ask why the loss of data can be tolerated in any case. Lossy compression techniques attempt to eliminate unnecessary or redundant information, focusing more on saving space over preserving the accuracy of the data. Ideally, the loss is either minimal or undetectable by human observations. Lossy compression techniques are used for pictures and music files that can be trimmed at the edges. Unlike text files and processing files, pictures and music do not require reconstruction to be identical to the original, especially if the data dropped is insignificant or undetectable.

This section will introduce lossy compression in JPEG and MP3 technology.

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