A photo can look untouched and still tell you it was edited.
Re-encoding signal (JPEG): camera firmware hardcodes Huffman and DQT tables per model. Software re-encoders compute optimised tables per image. Measurably different. Strip all metadata — the signature is still in the compression structure.
WebP uses VP8 predictive coding, not JPEG's DCT approach — but the same forensic logic applies. Firmware produces consistent parameter sets; software produces different ones.
Manufacturer baseline: camera firmware outputs a defined metadata fingerprint — GPS precision, MakerNote structure, timestamp format per model. A deviation from the expected profile is a finding. Applies to JPEG, WebP, MP4, MKV.
ELA: algorithmic, not visual. Re-compress, subtract, map the residual. Edited regions respond differently. Lossless formats rely on metadata only.
None conclusive alone. Three consistent signals: different conversation.
Full article (+ 30 more checks): https://kennethbspringer.au/how-to-tell-if-a-photo-has-been-edited/
Run any file: https://snapwonders.com/upload/analyse-photo-or-image









