Lossy

Compression that discards detail to save size, betting you will not notice. Most of what you watch is a careful loss.

Lossy compression is a wager on inattention: discard what the model says eyes will not miss, and pocket the size. The wager usually pays, most of what the world watches is a careful loss, and the care is the codec's century of perceptual research about what can vanish unmourned.

A careful loss curdles into a careless one through repetition and greed: re-encoding the already-encoded, rates starved below the content's needs. Each generation forgets more, and the forgetting is cumulative and permanent. The rules hold: one loss, at delivery, from a clean master, sized to the surface, judged by eye on the far end.