Glossary
Searchable terminology from accessibility, web standards, and related fields.
81 results found in computer vision.
- AR Marker (Fiducial marker, Augmented reality marker)
- A printed visual pattern (often a square with a distinctive black-and-white code) placed in the environment that a smartphone or AR headset camera can recognise to determine its own position and orien…
- Background Subtraction (Foreground-Background Separation, Background Modelling)
- Background subtraction is a computer vision technique used to identify moving objects (the foreground) in a video by comparing each frame against a model of the static background. Common approaches in…
- CLIP (Contrastive Language-Image Pre-Training)
- A vision-language model developed by OpenAI that learns to associate images with natural language descriptions through contrastive learning on large-scale image-text pairs. CLIP can compute similarity…
- Camera Framing (Photo Framing, Object Framing)
- The act of positioning a camera so that the intended subject is properly captured within the image frame — not cropped, not too small, and centered enough for clear identification. Camera framing pres…
- Camera Mouse (Head-Controlled Mouse Pointer, Head Tracking Mouse)
- A computer-vision-based mouse-replacement system that tracks a user's head motion through a standard webcam to control the mouse pointer on screen. Developed at Boston University by Margrit Betke and …
- Cascading classifier (Cascaded detection, Multi-stage classifier)
- A machine learning architecture that chains multiple detection stages in sequence, where each stage filters candidates before passing them to the next, progressively increasing detection precision whi…
- Cognitive Assistance (Cognitive Aid, AI-Powered Assistance, Assisted Cognition)
- Technology that uses artificial intelligence and machine learning to supplement or expand human cognitive and perceptual abilities. In accessibility contexts, cognitive assistance systems recognise pe…
- Collision Prediction (Collision risk prediction, Trajectory prediction)
- The task of estimating the future trajectories of surrounding pedestrians and obstacles and determining whether any of them will intersect with a user's own future position within a short prediction h…
- Color Histogram (Colour histogram, Histogram tracking)
- A statistical summary of the distribution of colour values across the pixels of an image or image region, often computed in a perceptual colour space such as Lab. In assistive computer-vision systems …
- Continuous Sign Language Recognition (CSLR)
- A computer vision task that involves recognizing sign language from continuous, naturally produced signing — as opposed to isolated sign recognition, which identifies individual signs in segmented cli…
- Convolutional Neural Network (CNN, ConvNet)
- A class of deep neural network that uses convolutional filters to automatically extract spatial features from data, originally designed for image processing but now widely applied to sensor data, audi…
- Crosswalk detection (Pedestrian crossing detection, Zebra crossing detection)
- The automated identification and localization of marked pedestrian crossings in imagery using computer vision techniques. Crosswalk detection can be performed on satellite images, street-level photogr…
- Depth Camera (Depth Sensor, RGB-D Camera, 3D Camera)
- A depth camera is a device that captures both standard visual imagery and per-pixel distance information, producing a 3D representation of the scene. Technologies include structured light (projecting …
- Face Detection (Face Recognition, Facial Detection)
- A computer vision technology that identifies and locates human faces within digital images or video frames, typically providing bounding box coordinates around each detected face. Face detection serve…
- Face Recognition (Facial Recognition, Face Detection)
- A technology that uses computer vision and machine learning to identify or verify a person by analysing their facial features from images or video. In accessibility contexts, face recognition has sign…
- Facial Action Coding System (FACS)
- A comprehensive, anatomically based system for describing all visually discernible facial movements, originally developed by Paul Ekman and Wallace Friesen in 1977. FACS decomposes facial expressions …
- Facial Expression Recognition (FER, Facial Action Recognition)
- Computer vision technology that detects and classifies facial expressions from images or video. In sign language contexts, facial expression recognition is essential for capturing non-manual signs — t…
- Fiducial Marker (ArUco Marker, Fiducial Tag)
- A visual pattern placed on an object or surface that can be detected and identified by computer vision systems to determine the object's position, orientation, and identity. Fiducial markers such as A…
- Fiducial Marker (AR Marker, Visual Marker, Reference Marker)
- An artificial visual landmark placed in a physical environment to serve as a reference point for image processing systems. Fiducial markers — such as QR codes, ArUco markers, and BCH matricial markers…
- Finger Tracking (Fingertip Tracking, Finger Detection, Hand Tracking)
- Computer vision or sensor-based technology that detects and follows the position and movement of a user's fingers in real-time. In accessibility applications, finger tracking enables hands-free intera…