getPerspectiveTransform

geometryfunctionOpenCV 5.0.0

import { getPerspectiveTransform } from '@banou/opencv-wasm'

Use after await initOpenCV(). See the initialization and named imports guide.

Explore visually: Homography and RANSAC →

Estimate a projective mapping between two views of a plane, rejecting inconsistent point matches.

VISUAL WALKTHROUGHGeometry

REFERENCE INPUTTentative correspondences

Eight tentative matches include two inconsistent pairs, shown in orange.

→

RESULTRecover the projective plane

The accepted mapping bends a rectangular grid into perspective. Every grid intersection uses the same projective transform as the inlier points.

Illustrative example. The stages explain the method; they are not a live OpenCV execution.

Calculates a perspective transform from four pairs of the corresponding points.

The function calculates the 3 \times 3 matrix of a perspective transform so that:

\begin{bmatrix} t_i x'_i \\ t_i y'_i \\ t_i \end{bmatrix} = \texttt{map_matrix} \cdot \begin{bmatrix} x_i \\ y_i \\ 1 \end{bmatrix}

where

dst(i)=(x'_i,y'_i), src(i)=(x_i, y_i), i=0,1,2,3

See: findHomography, warpPerspective, perspectiveTransform

getPerspectiveTransform(src: Mat, dst: Mat, solveMethod: number): Mat;

2 available overloads

getPerspectiveTransform(src: Mat, dst: Mat): Mat;

getPerspectiveTransform(src: Mat, dst: Mat, solveMethod: number): Mat;

src

Coordinates of quadrangle vertices in the source image.

dst

Coordinates of the corresponding quadrangle vertices in the destination image.

solveMethod

method passed to cv::solve (#DecompTypes)

Returns

The Mat result. Release returned native handles with using or delete(), including handles nested in results.

Upstream declaration ↗

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