# vlfeat/vlfeat

An open library of computer vision algorithms

Repository: https://github.com/vlfeat/vlfeat
Canonical: https://ross.abutalabs.com/products/vlfeat
Homepage: http://vlfeat.org/
Language: C
License: BSD-2-Clause
License Family: permissive
Last push: 2022-08-25T07:57:03+00:00

## Health v2 (maintenance only)
Score: 32/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 0, release rhythm 35, longevity 100
- inputs: {"age_days": 6329, "days_push": 1469, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_releases
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1648, forks 619 (observed 2026-08-28T04:05:16.597251+00:00)

## What it is
VLFeat is an open-source C library of popular computer vision algorithms specializing in image understanding and local feature extraction and matching, including SIFT, MSER, HOG, Fisher Vector, VLAD, k-means, and SVM training. It ships with a MATLAB/Octave toolbox and command-line utilities, and supports Windows, Mac OS X, and Linux.

## Use cases
- extract SIFT features from images
- detect MSER regions in an image
- compute HOG descriptors for object detection
- train large-scale SVM classifiers
- cluster visual features with k-means
- encode image features with Fisher vectors or VLAD
- segment images into superpixels with SLIC or quick shift
- match local features for image stitching

## When to choose
- you need classic computer vision feature extraction (SIFT, MSER, HOG) in C or MATLAB
- you want efficient, portable, BSD-licensed vision algorithms without heavy dependencies
- you are doing research or teaching with MATLAB and need vision algorithms
- you need Fisher Vector/VLAD encodings for image classification pipelines

## When to avoid
- you need deep learning or GPU-accelerated models rather than classical vision algorithms
- you need actively developed software with frequent updates and modern language bindings
- you require Python-first tooling with a modern API
- you need real-time or mobile-optimized vision inference

## Facets
- artifact type: library
- maturity: maintenance
- function: computer-vision, image-processing, machine-learning, math
- domain: computer-vision, image-processing, machine-learning
- platform: windows, cpp, python
- tags: sift, mser, feature-extraction, matlab-toolbox, fisher-vector, vlad, kmeans, svm, superpixels, c-library, algorithms, linux, macos

## Member repositories
- vlfeat/vlfeat (main) score 32

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:05:16.597251+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 2026-08-30T03:45:15.804589+00:00, confidence not recorded.
  - readme: https://github.com/vlfeat/vlfeat (fetched 2026-08-28T04:05:16.597251+00:00, sha 5093c6b722ee)
  - homepage: http://vlfeat.org/ (fetched 2026-08-29T11:18:36.447533+00:00, sha 801a8fdf764d)
  - site_page: https://www.vlfeat.org/about.html (fetched 2026-08-29T11:18:36.457187+00:00, sha bdfb206be2b9)
  - site_page: https://www.vlfeat.org/install-matlab.html (fetched 2026-08-29T11:18:36.459202+00:00, sha a209748b7c02)
  - site_page: https://www.vlfeat.org/install-octave.html (fetched 2026-08-29T11:18:36.460983+00:00, sha f33fb5fddabc)
  - site_page: https://www.vlfeat.org/install-shell.html (fetched 2026-08-29T11:18:36.462755+00:00, sha 6122455aa14e)
  - site_page: https://www.vlfeat.org/install-c.html (fetched 2026-08-29T11:18:36.464418+00:00, sha 254fef3760c3)
  - site_page: https://www.vlfeat.org/overview/hog.html (fetched 2026-08-29T11:18:36.466103+00:00, sha b9388b7e58c8)
  - site_page: https://www.vlfeat.org/doc.html (fetched 2026-08-29T11:18:36.467838+00:00, sha 0d45c2c3fcea)
  - site_page: https://www.vlfeat.org/download.html (fetched 2026-08-29T11:18:36.469272+00:00, sha 35002d454ae6)
- Data as of 2026-08-30T08:39:29.467469+00:00.