Image Compression

Image compression reduces the storage footprint of digital images produced when paper or other physical records are scanned or photographed, encoding the same picture using fewer bytes. It comes in two broad families: lossless compression, which reconstructs the original image exactly, and lossy compression, which permanently discards detail the algorithm deems less perceptible in exchange for much smaller files.

In recordkeeping this distinction is consequential. Aggressive lossy compression can degrade fine detail, blur small text, or introduce artifacts that compromise the legibility, authenticity, and evidentiary value of a record, which is why preservation and archival capture generally favor lossless methods or carefully controlled quality settings. For example, a contract scanned with heavy lossy compression might save space but render signatures or footnotes unreadable, undermining its use in audits or litigation.

Sound digitization programs document their compression choices as technical metadata so future custodians understand exactly how the master image was created and whether it faithfully represents the source.