What is Error level analysis (ELA)? (ELA)

ChronoVerify glossary

Error level analysis re-saves a JPEG at a known quality and measures where the compression error is uneven, which can highlight a region that was edited and pasted in. It is a weak, probabilistic signal that is unreliable on screenshots and recompressed images. ChronoVerify uses a localized ELA ratio only as a corroborator: a manipulation flag also requires a second independent signal, so a noisy ELA value alone never accuses a photo.

Why it matters

Error level analysis (ELA) is one of the signals ChronoVerify reads when you check a photo's capture time and provenance. No single signal is proof on its own: the verdict combines provenance, metadata, and pixel forensics, and is investigative triage for human review, not a courtroom guarantee.