Forward mapping - Forward mapping is an image-warping approach that takes locations in a source image and calculates where they go in a destination image.
Forward operator - A forward operator is a mathematical rule that maps an underlying object, signal or set of parameters to the observations a model predicts.
Fourier slice theorem - The Fourier slice theorem states that the one-dimensional Fourier transform of a parallel projection of a two-dimensional function equals a line through the...
Fourier space - Fourier space is a representation of a signal or image in terms of frequency components rather than its original time or spatial coordinates.
Fractal surface - A fractal surface is a surface model with irregular structure that follows a scaling relationship across levels of detail.
Frame averaging - Frame averaging combines corresponding pixel values from multiple images, usually by taking their mean, to produce one output image.
Frame buffer - A frame buffer is memory used to hold image data for a frame, such as the pixels being rendered or prepared for display.
Frame interpolation - Frame interpolation creates estimated images at times between existing video frames or related photographs.
Full-reference metric - A full-reference metric evaluates the quality or similarity of an image or video by comparing it with a complete reference version.
Gabor filter - A Gabor filter is a filter formed by combining a sinusoidal pattern with a Gaussian envelope.
Gabor transform - The Gabor transform is a time-frequency representation obtained by applying a Fourier transform to a signal viewed through a shifted Gaussian window.
Galerkin approximation - A Galerkin approximation represents an unknown solution using a finite set of basis functions and chooses their coefficients so that the equation's residual...
Gamma correction - Gamma correction is a nonlinear adjustment of image values used to account for, encode or modify the relationship between numerical values and light or...
Gamma encoding - Gamma encoding is the use of a nonlinear transfer curve to represent linear-light image values as stored or transmitted code values.
Gaussian blur - Gaussian blur smooths an image by replacing each pixel with a weighted combination of neighboring values, using weights shaped like a Gaussian distribution.
Generalized Hough transform - The generalized Hough transform is a shape-detection method that lets image features vote for possible locations and, in suitable variants, orientations and...
Geodesic distance - Geodesic distance is the length of a shortest permitted path between two points within a specified surface or domain.
Geographic information system (GIS) - A geographic information system, or GIS, is a system for managing, analyzing and displaying information linked to geographic locations.
Geometric model - A geometric model is a mathematical or digital representation of an object's shape, size and spatial structure.
GOP (group of pictures) - A GOP, or group of pictures, is a grouping or prediction structure within compressed video, commonly organized around successive keyframe or refresh points.
Gradient domain - The gradient domain is a way of working with an image through its local changes in value rather than directly through its absolute pixel values.
Gradient reversal - Gradient reversal is an image-processing artifact in which a local brightness change reverses direction after processing: a region that originally became...
Gram matrix - A Gram matrix records the pairwise inner products of a set of vectors.
Graph cut optimization - Graph cut optimization solves certain labeling problems by constructing a weighted graph whose cuts correspond to candidate solutions.
Graph-cut segmentation - Graph-cut segmentation divides an image into labeled regions by constructing a weighted graph and finding a cut that minimizes a defined cost.
Graph isomorphism - Graph isomorphism is a one-to-one correspondence between the vertices of two graphs that preserves their connections.
Graph kernel - A graph kernel is a function that compares two graphs in a way suitable for kernel-based learning, typically corresponding to an inner product between their...
Graph matching - Graph matching seeks a correspondence between vertices, edges or substructures of two graphs so that their attributes and relationships agree as well as the...
Graph partitioning - Graph partitioning divides a graph's vertices into groups according to a defined objective and constraints.
Graph representation - A graph representation describes entities as vertices and relationships as edges, together with any relevant attributes.
Gray scale - Gray scale, commonly written grayscale, represents an image using a single intensity-related value at each pixel rather than separate color components.
Gray-world assumption - The gray-world assumption is the idea that the average surface color across a sufficiently varied scene is approximately neutral.
Greedy search - Greedy search is an approach that repeatedly chooses the option that appears best according to a local rule.
Green-based demosaicking - Green-based demosaicking reconstructs a full-color image from a color-filter mosaic by using the green channel as a structural reference for estimating...
Guidance field - A guidance field, in gradient-domain image editing, is a set of desired local intensity changes that guides reconstruction of an output image.
Guided filter - A guided filter is an image filter that uses a guidance image to shape how an input image or map is smoothed.
Hadamard transform - The Hadamard transform represents a signal using patterns built from plus and minus signs rather than sinusoidal waves.
Hankel transform - The Hankel transform is an integral transform using Bessel functions that is especially useful for problems with radial or cylindrical symmetry.
Harmonic function - A harmonic function is a sufficiently smooth scalar function whose Laplacian is zero within a region.
Harmonization - Image harmonization adjusts the appearance of image elements so they look visually consistent when combined.
Harris corner detector - The Harris corner detector identifies image locations where brightness changes strongly in more than one direction.
Hartley transform - The Hartley transform is a real-valued transform closely related to the Fourier transform.
Hausdorff distance - Hausdorff distance measures the greatest nearest-neighbor separation between two sets of points.
Hays - Efros scene completion - Hays - Efros scene completion is a research approach that fills missing image regions by retrieving compatible content from a very large photograph collection.
HDR (high dynamic range) - HDR, or high dynamic range, describes imaging representations or systems that handle a broad range between dark and bright values.
HDR merging - HDR merging combines multiple measurements of the same scene to produce an image representation with useful information across a wider brightness range.
HDR-VDP - HDR-VDP is a family of visual-difference prediction methods designed to estimate how people perceive differences between images across a broad luminance range.