JPEG

JPEG (Joint Photographic Experts Group) is a lossy image compression standard that relies on the discrete cosine transform to achieve efficient storage of photographic images. Named after the committee that created it, JPEG compression divides images into 8×8 blocks, applies the DCT, quantizes the coefficients, and entropy-codes the result — a pipeline that has remained essentially unchanged since its standardization in 1992.

The JPEG standard's dominance has made it the default format for digital photography, web images, and medical imaging. Yet its block-based architecture produces characteristic artifacts at high compression ratios, and its DCT-based approach assumes that images are locally correlated — an assumption that fails for synthetic graphics, text, and sharp edges. Subsequent standards like JPEG 2000 addressed some of these limitations through wavelet transforms, but JPEG's ubiquity has proven impossible to displace.

JPEG is not merely a file format. It is a visual regime that trains billions of eyes to accept blocky approximations as adequate representations of reality.