Decompressors

A decompressor is a device or process that reverses compression. In information technology, it converts compressed data back into its original form. In fluid or gas systems, it expands a pressurized stream to a lower pressure, often using a regulator, valve, or expansion mechanism. Decompressors in one domain are not interchangeable with those in another, but the underlying principle is the same: reduce redundancy or energy by returning to an uncompressed state or to ambient pressure.

In data processing, a decompressor reads a compressed bitstream and reconstructs the original data using the corresponding encoding model. Lossless decompression restores every bit exactly; lossy decompression accepts some information loss to achieve higher compression ratios. Common algorithms include DEFLATE (used in ZIP and gzip), LZ77 variants, Huffman coding, and arithmetic coding. Formats such as ZIP, gzip, PNG, and JPEG embed decompression logic, and many implementations support streaming, partial data handling, and error detection.

In gas or hydraulic systems, decompression devices lower pressure to safe operating levels. In scuba diving, regulators act as pressure-reducing devices to supply breathable air; divers follow decompression schedules to ascend safely, with decompression chambers used to treat decompression sickness. In industrial contexts, expansion valves, pressure regulators, and similar components perform controlled decompression of compressed fluids or gases.

Related topics include data compression, lossless and lossy coding, decompression algorithms, and pressure regulation.