# kornelski/dssim

Image similarity comparison simulating human perception (multiscale SSIM in Rust)

Repository: https://github.com/kornelski/dssim
Canonical: https://ross.abutalabs.com/products/dssim
Homepage: https://kornel.ski/dssim
Language: Rust
License: AGPL-3.0
License Family: copyleft
Topics: dssim, compress-images, libpng, comparison, c, ssim, similarity, similarity-measurement, image-benchmark
Last push: 2026-08-29T20:15:45+00:00

## Health v2 (maintenance only)
Score: 68/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 100, release rhythm 8, longevity 100
- inputs: {"age_days": 5674, "days_push": 4, "days_rel": 546, "gap_med": null, "n_releases_24m": 1}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1194, forks 82 (observed 2026-09-01T02:14:03.545453+00:00)

## What it is
DSSIM is a Rust CLI tool and library that measures perceptual (dis)similarity between PNG/JPEG images using a multi-scale variant of the SSIM algorithm in L*a*b* color space. It outputs a difference score (0 = identical) and can generate visual difference maps, and is usable as a library from C, Rust, and WASM.

## Use cases
- compare two images for perceptual differences
- benchmark image compression codecs by visual quality
- detect chroma subsampling artifacts in compressed images
- generate a visual difference map between original and modified images
- batch-compare multiple compressed images against an original
- programmatically compute image similarity from Rust or C

## When to choose
- you need a perceptual image similarity metric more accurate than plain PSNR or basic SSIM
- you're benchmarking image compression codecs fairly at equal file sizes
- you want a dependency-free, multi-core CLI without OpenCV or MATLAB
- you need alpha channel and color profile aware comparison

## When to avoid
- you need scores directly comparable with other SSIM tools (DSSIM values are on its own scale)
- you require a percentage-based difference metric
- your project can't use AGPL-3.0 licensed code

## Facets
- artifact type: cli-tool
- maturity: active
- function: image-processing, benchmarking, cli
- domain: image-processing, graphics, developer-tools
- platform: windows, rust, cli
- tags: ssim, image-similarity, perceptual-metric, image-compression-benchmark, lab-color-space, c-api, wasm, linux, macos

## Member repositories
- kornelski/dssim (main) score 68

## Provenance
- Observed fields: from GitHub, fetched 2026-09-01T02:14:03.545453+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T06:22:13.856352+00:00, confidence not recorded.
  - readme: https://github.com/kornelski/dssim (fetched 2026-09-01T02:14:03.545453+00:00, sha 2d512137a0aa)
  - homepage: https://kornel.ski/dssim (fetched 2026-08-29T12:29:26.232511+00:00, sha d87572a978ff)
  - site_page: https://kornel.ski/about (fetched 2026-08-29T12:29:26.241407+00:00, sha f493d1825469)
  - registry_crates: https://crates.io/api/v1/crates/dssim (fetched 2026-08-29T12:29:26.243092+00:00, sha 14a3f23ebabd)
- Data as of 2026-08-30T08:39:29.467469+00:00.