Glossary
Searchable terminology from accessibility, web standards, and related fields.
42 results found in Computer Vision.
- Linear Discriminant Analysis (Fisher Discriminant Analysis, Fisherfaces)
- A statistical method used in pattern recognition and machine learning that finds a linear combination of features to best separate two or more classes of objects. In the context of face recognition, L…
- Motion History Image (MHI)
- A computer vision technique that represents motion in video sequences as a single grayscale image, where pixel intensity indicates recency of movement. Brighter pixels represent more recent motion whi…
- OCR (Optical Character Recognition) (OCR, Optical Character Recognition, Text Recognition)
- A computer-vision technology that converts images of printed, handwritten, or on-screen text into machine-readable character data. OCR is foundational to a wide range of accessibility tools: extractin…
- ORBIT Dataset (Object Recognition for Blind Image Training)
- A disability-first machine learning dataset for teachable object recognition, contributed by people who are blind or have low vision. The original ORBIT dataset (Massiceti et al., 2021) contains 3,822…
- Open-Vocabulary Detection (Open-Vocabulary Object Detection, OVD)
- A class of computer vision object detection models that accept arbitrary text queries at inference time rather than being restricted to a fixed set of pre-trained classes. Instead of only recognizing,…
- OpenPose
- An open-source computer vision library developed by Carnegie Mellon University that detects human body, hand, facial, and foot keypoints in real-time from images or video. OpenPose extracts 25 body ke…
- Optical Flow
- A computer vision method that estimates the apparent motion of objects between consecutive video frames by tracking pixel displacement patterns. Optical flow calculates velocity vectors showing moveme…
- Personalized Object Recognition (Teachable Object Recognition)
- A class of computer vision systems that allow an individual user — typically someone who is blind or has low vision — to train their device to recognize a small set of personally relevant objects (a s…
- Phase-Based Motion Processing (Phase-Based Video Motion Processing, Phase-Based Motion Magnification)
- A family of computer vision techniques that decompose video frames into complex steerable pyramids and analyse changes in the temporal phase of each scale and orientation to recover motion, including …
- Principal Component Analysis (PCA)
- A statistical technique that reduces the dimensionality of data by identifying the principal axes of variation in a dataset. In accessibility and assistive technology contexts, PCA is commonly used in…
- RGBD Camera (RGB-D Camera, Depth Camera, Stereo Camera)
- A camera that captures both a colour (RGB) image and a per-pixel depth (D) measurement of the scene, yielding a 3D representation of the environment. Depth can be produced by stereo vision, structured…
- Sign Spotting (Sign Detection, Continuous Sign Spotting)
- Sign spotting is the task of automatically locating instances of specific signs within a continuous signing video, as opposed to classifying a pre-segmented isolated sign. It is a building block for s…
- Spatiotemporal Saliency (Spatiotemporal Saliency Estimation, Spatio-Temporal Saliency)
- A computer vision technique that estimates, for each pixel in a video, how visually important it is at a given moment by combining spatial contrast (features that stand out within a frame) with tempor…
- Stereo Vision (Stereoscopic Vision, Stereo Camera System, Stereopsis)
- A computer vision technique that uses two or more cameras positioned at slightly different viewpoints to extract three-dimensional depth information from a scene, mimicking the way human binocular vis…
- Stereoscopic Camera (Stereo Camera, Depth Camera, 3D Camera)
- A camera system that uses two or more lenses to capture images from slightly different perspectives, mimicking human binocular vision to compute depth information (disparity maps). In accessibility ap…
- Talking Head (Virtual Talking Head, Animated Face, 3D Talking Head, Virtual Speech Tutor)
- A talking head is a computer-generated 3D or 2D animated representation of a human face and articulatory system that produces visible speech movements synchronised with audio output. In accessibility …
- VQA (Visual Question Answering)
- VQA (Visual Question Answering) is an AI task in which a system answers natural-language questions about the content of an image. In assistive contexts, VQA systems such as Be My AI, Seeing AI, and Ai…
- Vision Language Model (VLM, Vision-Language Model, Multimodal Large Language Model)
- A machine-learning model trained to take both images and natural-language text as input and to produce natural-language output. Modern VLMs — such as GPT-4o, Gemini, and Claude — can describe a photo,…
- Visual Saliency (Saliency, Saliency Detection, Saliency Map)
- A computational measure of how much a particular region of an image or video stands out from its surroundings and attracts visual attention. Saliency models predict where people are most likely to loo…
- Visual-Inertial Odometry (VIO)
- A computer vision technique that combines camera imagery with motion sensor data (accelerometer and gyroscope) to track a device's position and orientation in 3D space. In accessibility applications, …