This list gives an overview of all modules available inside the contrib repository. To turn off building one of these module repositories, set the names in bold below to

$ cmake -D OPENCV_EXTRA_MODULES_PATH=<opencv_contrib>/modules -D BUILD_opencv_<reponame>=OFF <opencv_source_directory>

• alphamat: Computer Vision based Alpha Matting -- Given an input image and a trimap, generate an alpha matte.

• aruco: ArUco and ChArUco Markers -- Augmented reality ArUco marker and "ChARUco" markers where ArUco markers embedded inside the white areas of the checker board.

• barcode: Barcode detecting and decoding methods.

• bgsegm: Background segmentation algorithm combining statistical background image estimation and per-pixel Bayesian segmentation.

• bioinspired: Biological Vision -- Biologically inspired vision model: minimize noise and luminance variance, transient event segmentation, high dynamic range tone mapping methods.

• ccalib: Custom Calibration -- Patterns for 3D reconstruction, omnidirectional camera calibration, random pattern calibration and multi-camera calibration.

• cnn_3dobj: Deep Object Recognition and Pose -- Uses Caffe Deep Neural Net library to build, train and test a CNN model of visual object recognition and pose.

• cvv: Computer Vision Debugger -- Simple code that you can add to your program that pops up a GUI allowing you to interactively and visually debug computer vision programs.

• datasets: Datasets Reader -- Code for reading existing computer vision databases and samples of using the readers to train, test and run using that dataset's data.

• dnn_objdetect: Object Detection using CNNs -- Implements compact CNN Model for object detection. Trained using Caffe but uses opencv_dnn module.

• dnn_superres: Superresolution using CNNs -- Contains four trained convolutional neural networks to upscale images.

• dnns_easily_fooled: Subvert DNNs -- This code can use the activations in a network to fool the networks into recognizing something else.

• dpm: Deformable Part Model -- Felzenszwalb's Cascade with deformable parts object recognition code.

• face: Face Recognition -- Face recognition techniques: Eigen, Fisher and Local Binary Pattern Histograms LBPH methods.

• freetype: Drawing text using freetype and harfbuzz.

• fuzzy: Fuzzy Logic in Vision -- Fuzzy logic image transform and inverse; Fuzzy image processing.

• hdf: Hierarchical Data Storage -- This module contains I/O routines for Hierarchical Data Format: https://en.m.wikipedia.org/wiki/Hierarchical_Data_Format meant to store large amounts of data.

• hfs: Hierarchical Feature Selection for Efficient Image Segmentation -- This module contains an efficient algorithm to segment an image.

• img_hash: This module contains algorithms to extract hash of an image allowing to efficiently estimate similarity between images.

• intensity_transform: The module brings implementations of intensity transformation algorithms to adjust image contrast.

• julia: Julia language wrappers with samples and tests.

• line_descriptor: Line Segment Extract and Match -- Methods of extracting, describing and matching line segments using binary descriptors.

• matlab: Matlab Interface -- OpenCV Matlab Mex wrapper code generator for certain opencv core modules.

• mcc: Macbeth Color Chart detector -- Find and return color patch location in MacBeth color calibration charts.

• optflow: Optical Flow -- Algorithms for running and evaluating deepflow, simpleflow, sparsetodenseflow and motion templates (silhouette flow).

• ovis: OGRE 3D Visualiser -- allows you to render 3D data using the OGRE 3D engine.

• phase_unwrapping: Quality-guided phase unwrapping.

• plot: Plotting -- The plot module allows you to easily plot data in 1D or 2D.

• quality: Image Quality Analysis (IQA) API.

• rapid: Silhouette based 3D object tracking.

• reg: Image Registration -- Pixels based image registration for precise alignment. Follows the paper "Image Alignment and Stitching: A Tutorial", by Richard Szeliski.

• rgbd: RGB-Depth Processing module -- Linemod 3D object recognition; Fast surface normals and 3D plane finding. 3D visual odometry. 3d reconstruction using KinectFusion.

• saliency: Saliency API -- Where humans would look in a scene. Has routines for static, motion and "objectness" saliency.

• sfm: Structure from Motion -- This module contains algorithms to perform 3d reconstruction from 2d images. The core of the module is a light version of Libmv.

• shape: Shape Distance and Matching

• stereo: Stereo Correspondence -- Stereo matching done with different descriptors: Census / CS-Census / MCT / BRIEF / MV and dense stereo correspondence using Quasi Dense Stereo method.

• structured_light: Structured Light Use -- How to generate and project gray code patterns and use them to find dense depth in a scene.

• superres: Super Resolution

• surface_matching: Point Pair Features -- Implements 3d object detection and localization using multimodal point pair features.

• text: Scene Text Detection and Recognition -- This module contains algorithms to perform text detection, words segmentation and text recognition in a visual scene.

• tracking: Vision Based Object Tracking -- Use and/or evaluate different visual object tracking techniques.

• videostab: Video Stabilization

• viz: 3D Visualizer

• wechat_qrcode: WeChat QR code detector for detecting and parsing QR code.

• xfeatures2d: Features2D extra -- Extra 2D Features Framework containing experimental and non-free 2D feature detector/descriptor algorithms. SURF, BRIEF, Censure, Freak, LUCID, Daisy, Self-similar.

• ximgproc: Extended Image Processing -- Structured Forests / Domain Transform Filter / Guided Filter / Adaptive Manifold Filter / Joint Bilateral Filter / Superpixels / Ridge Detection Filter.

• xobjdetect: Boosted 2D Object Detection -- Uses a Waldboost cascade and local binary patterns computed as integral features for 2D object detection.

• xphoto: Extra Computational Photography -- Additional photo processing algorithms: Color balance / Denoising / Inpainting.