Blockhash (perceptual)

POST /api/image-hash-blockhash

Compute a perceptual hash of an image (block-hash). Two visually-similar images produce hashes within a small Hamming distance. Useful for de-duplication and reverse-image-search.

Computes a perceptual hash — a fingerprint that survives minor pixel-level differences (compression, slight resizing, small watermarks). Two visually-similar images produce hashes within a small Hamming distance of each other. Output is a fixed-length hex string. Compare two images by computing their distance: 0 means identical, ~5 means very similar, 10+ means visibly different. Useful as the index key for image de-duplication, reverse- image search, and abuse-content filtering.

Inputs

Name	Type	Default	Description
image*	file	—	Input image bytes.

Response

Modes: json. Cache: yes (24h TTL).