The Hamsa Book · contents

The story

  1. 1The flood, and the videos that came after
  2. 2A triage desk, not an oracle
  3. 3One post, from a phone to a verdict

How it works

  1. 4Seeing footage before: three fingerprints
  2. 5Finding the evidence, in two languages
  3. 6Models propose, rules decide
  4. 7A memory, not a library
  5. 8Under the hood: one laptop, open models

The proof

  1. 9The numbers, and what went wrong
  2. 10What Hamsa does not do yet
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How it works · Chapter 4

Seeing footage before: three fingerprints

How Hamsa recognises a repost that has been cropped, mirrored or covered in captions, and why it needs three methods.

A repost is rarely an exact copy. It has been re-encoded by a platform, cropped to a phone screen, mirrored to dodge detection, covered with captions, or screenshotted. Comparing files byte by byte finds nothing. So Hamsa compares what the frames look like, three different ways.

Perceptual hash: 64 bitsre-encodes, resizes,light cropsEmbedding: 768 numbersthe same scene under captions,overlays and heavier editsKeypoints that line upproves the same shot insidecrops, bars and screenshots
One keyframe, three fingerprints. Each catches what the others miss, and none needs the video itself.
  • A perceptual hash shrinks a frame to 64 light-and-dark bits. Re-encoding and resizing barely change it. It is fast and exact, but a heavy edit breaks it.
  • An image embedding from an open model (SigLIP) turns a frame into 768 numbers that describe the scene. It still matches under captions and overlays, but on its own it would also match a different video of a similar river.
  • Keypoints (ORB) are distinctive corners and edges. When dozens of them line up in a consistent pattern between two frames, they are the same shot, not just a similar one. This is what stops the second method from fooling itself.

Mirrored frames are checked too. When there is a match, the checker sees the post's frame and the original side by side, with the original's date and source. They do not have to trust Hamsa; they can see it.