Editing Data compression ratio (section)

==Lossless vs. Lossy==
[[Lossless compression]] of digitized data such as video, digitized film, and audio preserves all the information, but it does not generally achieve compression ratio much better than 2:1 because of the intrinsic [[information entropy|entropy]] of the data. Compression algorithms which provide higher ratios either incur very large overheads or work only for specific data sequences (e.g. compressing a file with mostly zeros). In contrast, [[lossy compression]] (e.g. [[JPEG]] for images, or [[MP3]] and [[Opus (audio format)|Opus]] for audio) can achieve much higher compression ratios at the cost of a decrease in quality, such as Bluetooth audio streaming, as visual or audio compression artifacts from loss of important information are introduced. A compression ratio of at least 50:1 is needed to get [[1080i]] video into a 20&nbsp;Mbit/s [[MPEG transport stream]].<ref name=CompressionRatioBroadcastEngineering/>