Back to FabImage Studio website

You are here: Start » Filter Reference » OpenCV

OpenCV

Camera Calibration And 3D Reconstruction

Icon Name Description / Applications Modules
CreateCameraMatrix

Creates an intrinsic camera matrix from focal lengths and a principal point.

OpenCV
CreateChessboardMatrix

Creates simple array with object points.

OpenCV
CreateCirclesGridMatrix

Creates simple array with object points.

OpenCV
cvCalibrateRobotWorldHandEye

Computes Robot-World and Hand-Eye calibration matrices.

OpenCV
cvCalibrateCamera

Finds the camera intrinsic and extrinsic parameters from pairs of corresponding image and object points arrays.

OpenCV
cvCalibrateHandEye

Computes Hand-Eye calibration matrices.

OpenCV
cvCalibrationMatrixValues

Returns camera characteristics from camera matrix.

OpenCV
cvCheckChessboard

Check chessboard corners.

OpenCV
cvConvertPointsFromHomogeneous

Converts points from homogeneous to Euclidean space.

OpenCV
cvConvertPointsToHomogeneous

Converts points from Euclidean to homogeneous space.

OpenCV
cvCorrectMatches

Refines coordinates of corresponding points.

OpenCV
cvCorrespondEpilines

Computes epilines in one view for a set of points in the other view.

OpenCV
cvDecomposeEssentialMat

Decompose an essential matrix to possible rotations and translation.

OpenCV
cvDecomposeHomographyMat

Decompose a homography matrix to rotation(s), translation(s) and plane normal(s).

OpenCV
cvDecomposeProjectionMatrix

Decomposes a projection matrix into a rotation matrix and a camera intrinsic matrix.

OpenCV
cvDrawChessboardCorners

Renders the detected chessboard corners.

OpenCV
cvDrawFrameAxes

Draw axes of the world/object coordinate system from pose estimation.

OpenCV
cvEstimateAffine2D

Computes an optimal affine transformation between two 2D point sets.

OpenCV
cvEstimateAffine3D

Computes optimal affine transformation between two 3D point sets.

OpenCV
cvEstimateAffinePartial2D

Computes an optimal limited affine transformation with 4 degrees of freedom between two 2D point sets.

OpenCV
cvEstimateChessboardSharpness

Estimates the sharpness of a detected chessboard. Image sharpness, as well as brightness, are a critical parameter for accuracte camera calibration.

OpenCV
cvFindChessboardCorners

Finds the positions of the internal corners of the chessboard.

OpenCV
cvFindCirclesGrid

Finds the centers in the grid of circles.

OpenCV
cvFindEssentialMat

Calculates an essential matrix from the corresponding points in two images.

OpenCV
cvFindHomography

Finds a perspective transformation between two planes.

OpenCV
cvFisheyeCalibrateCamera

Finds the camera intrinsic and extrinsic parameters from pairs of corresponding image and object points arrays.

OpenCV
cvGetOptimalNewCameraMatrix

Computes the new camera matrix based on the free scaling parameter.

OpenCV
cvInitCameraMatrix2D

Finds the initial camera matrix from the 3D-2D point correspondences.

OpenCV
cvMatMulDeriv

Computes partial derivatives of the matrix product for each multiplied matrix.

OpenCV
cvProjectPoints

Projects 3D points to an image plane.

OpenCV
cvReprojectImageTo3D

Projects a disparity image to 3D space.

OpenCV
cvRodrigues_MatToVec

Converts a Rotation Matrix to a Rvec vector.

OpenCV
cvRodrigues_VecToMat

Converts a Rvec vector to a Rotation Matrix.

OpenCV
cvSolvePnP

Finds an object pose from 3D-2D point correspondences. This function returns the rotation and the translation vectors that transform a 3D point expressed in the object coordinate frame to the camera coordinate frame.

OpenCV
cvSolvePnPRansac

Finds an object pose from 3D-2D point correspondences using the RANSAC scheme.

OpenCV
cvSolvePnPRefineLM

Refine a pose (the translation and the rotation that transform a 3D point expressed in the object coordinate frame to the camera coordinate frame) from a 3D-2D point correspondences and starting from an initial solution.

OpenCV
cvSolvePnPRefineVVS

Refine a pose (the translation and the rotation that transform a 3D point expressed in the object coordinate frame to the camera coordinate frame) from a 3D-2D point correspondences and starting from an initial solution.

OpenCV
cvStereoBM

Computes stereo correspondence using the block matching algorithm.

OpenCV
cvStereoCalibrate

Performs stereo calibration of two cameras.

OpenCV
cvStereoRectify

Computes rectification transforms for each head of a calibrated stereo camera.

OpenCV
cvStereoSGBM

Computes stereo correspondence using the semi-global block matching algorithm.

OpenCV
cvTriangulatePoints

This function reconstructs 3-dimensional points (in homogeneous coordinates) by using their observations with a stereo camera.

OpenCV

Computational Photography

Icon Name Description / Applications Modules
cvColorChange

Given an original color image, two differently colored versions of this image can be mixed seamlessly.

OpenCV
cvDecolor

Transforms a color image to a grayscale image. It is a basic tool in digital printing, stylized black-and-white photograph rendering, and in many single channel image processing applications.

OpenCV
cvDenoise_TVL1

Primal-dual algorithm is an algorithm for solving special types of variational problems (that is, finding a function to minimize some functional). As the image denoising, in particular, may be seen as the variational problem, primal-dual algorithm then can be used to perform denoising and this is exactly what is implemented.

OpenCV
cvDetailEnhance

This filter enhances the details of a particular image.

OpenCV
cvEdgePreservingFilter

Filtering is the fundamental operation in image and video processing. Edge-preserving smoothing filters are used in many different applications.

OpenCV
cvFastNlMeansDenoising

Perform image denoising using Non-local Means Denoising algorithm.

OpenCV
cvFastNlMeansDenoisingColored

Perform image denoising using Non-local Means Denoising algorithm.

OpenCV
cvFastNlMeansDenoisingMulti

Perform image denoising using Non-local Means Denoising algorithm.

OpenCV
cvIlluminationChange

Applying an appropriate non-linear transformation to the gradient field inside the selection and then integrating back with a Poisson solver, modifies locally the apparent illumination of an image.

OpenCV
cvSeamlessClone

Image editing tasks concern either global changes (color/intensity corrections, filters, deformations) or local changes concerned to a selection.

OpenCV
cvTextureFlattening

By retaining only the gradients at edge locations, before integrating with the Poisson solver, one washes out the texture of the selected region, giving its contents a flat aspect. Here Canny Edge Detector is used.

OpenCV

Configuration

Icon Name Description / Applications Modules
cvSetNumThreads

Configures number of threads used by OpenCV.

OpenCV
cvSetUseOptimized

Enables or disables the optimized code.

OpenCV

Drawing

Icon Name Description / Applications Modules
cvArrowedLine

Draws a arrow segment connecting two points.

OpenCV
cvCircle

Draws a circle.

OpenCV
cvDrawMarker

Draws a marker on a predefined position in an image.

OpenCV
cvEllipse

Draws a simple or thick elliptic arc or fills an ellipse sector.

OpenCV
cvFillConvexPoly

Fills a convex shape.

OpenCV
cvFillPoly

Fills the area bounded by one or more polygons.

OpenCV
cvGetFontScaleFromHeight

Calculates the font-specific size to use to achieve a given height in pixels.

OpenCV
cvGetTextSize

Calculates the width and height of a text string.

OpenCV
cvLine

Draws a line segment connecting two points.

OpenCV
cvPolylines

Draws several polygonal curves.

OpenCV
cvPutText

Draws a text string.

OpenCV
cvRectangle

Draws a simple, thick, or filled up-right rectangle.

OpenCV

Feature 2D Framework

Icon Name Description / Applications Modules
cvBOWTrainerFeature2D

Kmeans-based class to train visual vocabulary using the bag of visual words approach.

OpenCV
cvDetectFeature2D_BRISK

BRISK keypoint detector and descriptor extractor.

OpenCV
cvDetectFeature2D_FastFeatureDetector

Feature detection using the FAST method.

OpenCV
cvDetectFeature2D_GFTT

Feature detection using the good features to track function.

OpenCV
cvDetectFeature2D_KAZE

KAZE keypoint detector and descriptor extractor.

OpenCV
cvDetectFeature2D_ORB

ORB keypoint detector and descriptor extractor.

OpenCV
cvDetectFeature2D_SIFT

Extracting keypoints and computing descriptors using the Scale Invariant Feature Transform (SIFT) algorithm.

OpenCV
cvDetectFeature2D_SimpleBlobDetector

Extracting blobs from an image.

OpenCV
cvMatchFeature2D

Matchers of keypoint descriptors.

OpenCV

Feature Detection

Icon Name Description / Applications Modules
cvCanny

Finds edges in an image using Canny algorithm.

OpenCV
cvCornerEigenValsAndVecs

Calculates eigenvalues and eigenvectors of image blocks for corner detection.

OpenCV
cvCornerHarris

Harris corner detector.

OpenCV
cvCornerMinEigenVal

Calculates the minimal eigenvalue of gradient matrices for corner detection.

OpenCV
cvCornerSubPix

Refines the corner locations.

OpenCV
cvGoodFeaturesToTrack

Determines strong corners on an image.

OpenCV
cvHoughCircles

Finds circles in a grayscale image using a Hough transform.

OpenCV
cvHoughLines

Finds lines in a binary image using standard Hough transform.

OpenCV
cvHoughLinesP

Finds lines segments in a binary image using probabilistic Hough transform.

OpenCV
cvPreCornerDetect

Calculates the feature map for corner detection.

OpenCV

Geometric Image Transformations

Icon Name Description / Applications Modules
cvGetAffineTransform

Calculates the affine transform from 3 corresponding points.


Prepares matrix to be used with cvWarpAffine.

OpenCV
cvGetDefaultNewCameraMatrix

Returns the default new camera matrix.

OpenCV
cvGetPerspectiveTransform

Calculates the perspective transform from four pairs of corresponding points.


Prepares matrix to be used with cvWarpPerspective.

OpenCV
cvGetRectSubPix

Retrieves the pixel rectangle from an image with sub-pixel accuracy.

OpenCV
cvGetRotationMatrix2D

Calculates the affine matrix of 2D rotation.


Prepares matrix to be used with cvWarpAffine.

OpenCV
cvInitUndistortRectifyMap

Computes the undistortion and rectification transformation map.

OpenCV
cvInvertAffineTransform

Inverts an affine transformation.


Prepares matrix to be used with cvWarpAffine.

OpenCV
cvRemap

Applies a generic geometrical transformation to the image.

OpenCV
cvResize

Resizes an image.

OpenCV
cvUndistort

Transforms an image to compensate for lens distortion.

OpenCV
cvUndistortPoints

Undistorts points.

OpenCV
cvWarpAffine

Applies an affine transformation to an image.

OpenCV
cvWarpPerspective

Applies a perspective transformation to an image.

OpenCV
cvWarpPolar

Remaps an image to polar or semilog-polar coordinates space.

OpenCV

Image Filtering

Icon Name Description / Applications Modules
cvBilateralFilter

Applies bilateral filter to the image.

OpenCV
cvBlur

Smoothes image using normalized box filter.

OpenCV
cvBorderInterpolate

Computes source location of extrapolated pixel.

OpenCV
cvBoxFilter

Smoothes an image using box filter.

OpenCV
cvBuildPyramid

Constructs Gaussian pyramid for an image.

OpenCV
cvCopyMakeBorder

Forms a border around the image.

OpenCV
cvDilate

Dilates an image by using a specific structuring element.

OpenCV
cvErode

Erodes an image by using a specific structuring element.

OpenCV
cvFilter2D

Convolves an image with the kernel.

OpenCV
cvGaussianBlur

Smoothes image using a Gaussian filter.

OpenCV
cvGetDerivKernels

Returns filter coefficients for computing spatial image derivatives.


Prepares matrices to be used with cvSepFilter2D or cvFilter2D.

OpenCV
cvGetGaborKernel

Creates a Gabor Filter kernel.


Prepares matrix to be used with cvSepFilter2D or cvFilter2D.

OpenCV
cvGetGaussianKernel

Returns Gaussian filter coefficients.


Prepares matrix to be used with cvSepFilter2D or cvFilter2D.

OpenCV
cvGetStructuringElement

Returns the structuring element of the specified size and shape for morphological operations.


Prepares element to be used with cvErode, cvDilate or cvMorphologyEx.

OpenCV
cvLaplacian

Calculates the Laplacian of an image.

OpenCV
cvMedianBlur

Smoothes image using median filter.

OpenCV
cvMorphologyDefaultBorderValue

Returns magic border value for erosion and dilation.

OpenCV
cvMorphologyEx

Performs advanced morphological transformations.

OpenCV
cvPyrDown

Smoothes an image and downsamples it.

OpenCV
cvPyrUp

Upsamples an image and then smoothes it.

OpenCV
cvScharr

Calculates the first x- or y- image derivative using Scharr operator.

OpenCV
cvSepFilter2D

Applies separable linear filter to an image.

OpenCV
cvSobel

Calculates the first, second, third or mixed image derivatives using an extended Sobel operator.

OpenCV
cvSqrBoxFilter

Smoothes an image using square box filter.

OpenCV

Miscellaneous Image Transformations

Icon Name Description / Applications Modules
cvAdaptiveThreshold

Applies an adaptive threshold to an image.

OpenCV
cvApplyColorMap

Apply color map to image.

OpenCV
cvBlendLinear

Blend images.

OpenCV
cvCvtColor

Converts image from one color space to another.

OpenCV
cvDistanceTransform

Calculates the distance to the closest zero pixel for each pixel of the source image.

OpenCV
cvFloodFill

Fills a connected component with the given color.

OpenCV
cvGrabCut

Runs the GrabCut algorithm.

OpenCV
cvInpaint

Inpaints the selected region in the image.

OpenCV
cvIntegral

Calculates the integral of an image.

OpenCV
cvPyrMeanShiftFiltering

Performs an initial step of Mean Shift Filtering algorithm.

OpenCV
cvThreshold

Applies a fixed-level threshold to each image element.

OpenCV
cvWatershed

Does marker-based image segmentation using watershed algorithm.

OpenCV

Motion Analysis and Object Tracking

Icon Name Description / Applications Modules
cvAccumulate

Adds image to the accumulator.

OpenCV
cvAccumulateProduct

Adds the per-element product of two input images to the accumulator.

OpenCV
cvAccumulateSquare

Adds the square of the source image to the accumulator.

OpenCV
cvAccumulateWeighted

Updates the running average.

OpenCV
cvBackgroundSubtractorKNN

K-nearest neighbours based background segmentation algorithm.

OpenCV
cvBackgroundSubtractorMOG2

Estimates the background of the image sequence using Mixture Of Gaussians model.

OpenCV
cvCamShift

Finds an moving object center, size, and orientation.

OpenCV
cvComputeECC

Computes the Enhanced Correlation Coefficient value between two images.

OpenCV
cvDISOpticalFlow

DIS optical flow algorithm.

OpenCV
cvFarnebackOpticalFlow

Computing a dense optical flow using the Gunnar Farneback's algorithm.

OpenCV
cvKalmanFilter

Standard Kalman filter.

OpenCV
cvPhaseCorrelate

The function is used to detect translational shifts that occur between two images.

OpenCV
cvSparsePyrLKOpticalFlow

Calculate an optical flow for a sparse feature set using the iterative Lucas-Kanade method with pyramids.

OpenCV

Object Detection

Icon Name Description / Applications Modules
cvMatchTemplate

Compares a template against overlapped image regions.

OpenCV

Histogram

Icon Name Description / Applications Modules
cvCalcBackProject

Calculates array histogram. This function perform cvCalcHist inside.

OpenCV
cvCalcHist

Calculates array histogram.

OpenCV
cvCLAHE

Equalizes histogram of image using adaptive histogram equalization.

OpenCV
cvCompareHist

The function compares two dense or two sparse histograms using the specified method.

OpenCV
cvEqualizeHist

Equalizes the histogram of a grayscale image.

OpenCV

Stitching

Icon Name Description / Applications Modules
cvStitching

Very simple high level image stitching.

OpenCV

Structural Analysis and Shape Descriptors

Icon Name Description / Applications Modules
cvApproxPolyDP

Approximates polygonal curve(s) with the specified precision.

OpenCV
cvArcLength

Calculates a contour perimeter or a curve length.

OpenCV
cvBoundingRect

Calculates the up-right bounding rectangle of a point set.

OpenCV
cvConnectedComponents

Computes the connected components labeled image of boolean image.

OpenCV
cvConnectedComponentsWithStats

Computes the connected components labeled image of boolean image and also produces a statistics output for each label

OpenCV
cvContourArea

Calculates the contour area.

OpenCV
cvConvexHull

Finds the convex hull of a point set.

OpenCV
cvDrawContours

Draws contour outlines or filled contours.

OpenCV
cvFindContours

Finds the contours in a binary image.

OpenCV
cvFitEllipse

Fits an ellipse around a set of 2D points.

OpenCV
cvFitEllipseAMS

Fits an ellipse around a set of 2D points.

OpenCV
cvFitEllipseDirect

Fits an ellipse around a set of 2D points.

OpenCV
cvFitLine

Fits a line to a 2D or 3D point set.

OpenCV
cvGeneralizedHoughBallard_Detection

Finds arbitrary template in the grayscale image using Generalized Hough Transform.

OpenCV
cvGeneralizedHoughBallard_Initialization

Finds arbitrary template in the grayscale image using Generalized Hough Transform.

OpenCV
cvGeneralizedHoughGuil_Detection

Finds arbitrary template in the grayscale image using Generalized Hough Transform.

OpenCV
cvGeneralizedHoughGuil_Initialization

Finds arbitrary template in the grayscale image using Generalized Hough Transform.

OpenCV
cvHuMoments

Calculates Hu moments of the image.

OpenCV
cvIntersectConvexConvex

Finds intersection of two convex polygons.

OpenCV
cvIsContourConvex

Tests contour convexity.

OpenCV
cvMatchShapes_Images

Compares two shapes.

OpenCV
cvMatchShapes_Polygon

Compares two shapes.

OpenCV
cvMinAreaRect

Finds a rotated rectangle of the minimum area enclosing the input 2D point set.

OpenCV
cvMinEnclosingCircle

Finds the minimum area circle enclosing a 2D point set.

OpenCV
cvMinEnclosingTriangle

Finds a rotated triangle of the minimum area enclosing the input 2D point set.

OpenCV
cvMoments

Calculates image moments.

OpenCV
cvPointPolygonTest

Performs point-in-contour test.

OpenCV

Video Analysis

Icon Name Description / Applications Modules
cvCalcOpticalFlowFarneback

Computes a dense optical flow using the Gunnar Farneback's algorithm.

OpenCV
cvCalcOpticalFlowPyrLK

Calculates an optical flow for a sparse feature set using the iterative Lucas-Kanade method with pyramids.

OpenCV