Lossless Compression is a method of data compression which preserves all data so that the original file is perfectly reconstructed after decompression. It works by replacing data inside the file with shorter code words, keeping all the original information intact. Compared to Lossy Compression methods, which discard data from files, Lossless Compression produces an exact replica of the original file, but at a much reduced size.
Lossless Compression exploits patterns found in data files. Since most data files contain a certain amount of redundant information, Lossless Compression is able to save both memory and storage space by removing these redundancies. With Lossless Compression, the data is preserved while the file is made smaller.
The most popular algorithms used in Lossless Compression are the Deflate algorithm (also known as zip compression) and the Lempel-Ziv-Welch algorithm (LZW). Deflate and LZW are widely used, especially in graphic and audio files.
Lossless Compression is used extensively in web applications, especially when data is transferred over slow connections. Lossless Compression is a great way to reduce file size without any loss in quality, allowing for faster downloads and more efficient storage of files.
Lossless Compression can also be used to compress non-data files, such as executables (e.g. Windows programs). Compressing executable files can lead to a faster system overall, as the compressed executables take less time to load into memory.
The most important thing to remember about Lossless Compression is that it preserves the original data, ensuring an exact copy is created after decompression. This is an incredibly useful property, especially when dealing with sensitive data or high resolution images. While Lossless Compression will not be able to compress a file as much as Lossy Compression, the data integrity is guaranteed.
