convertMaps

Image processingfunctionOpenCV 5.0.0

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

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

Explore visually: Arbitrary remapping →

Provide a source coordinate for every destination pixel.

VISUAL WALKTHROUGHGeometry

REFERENCE INPUTFour neighbouring source samples

A magnified patch makes the interpolation arithmetic visible.

→

RESULTInterpolate one destination value

Repeat the mapping and interpolation for every destination pixel. Other interpolation flags use different sampling rules.

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

Converts image transformation maps from one representation to another.

The function converts a pair of maps for remap from one representation to another. The following options ( (map1.type(), map2.type()) \rightarrow (dstmap1.type(), dstmap2.type()) ) are supported:

• \texttt{(CV_32FC1, CV_32FC1)} \rightarrow \texttt{(CV_16SC2, CV_16UC1)}. This is the most frequently used conversion operation, in which the original floating-point maps (see #remap) are converted to a more compact and much faster fixed-point representation. The first output array contains the rounded coordinates and the second array (created only when nninterpolation=false ) contains indices in the interpolation tables.

• \texttt{(CV_32FC2)} \rightarrow \texttt{(CV_16SC2, CV_16UC1)}. The same as above but the original maps are stored in one 2-channel matrix.

• Reverse conversion. Obviously, the reconstructed floating-point maps will not be exactly the same as the originals.

See: remap, undistort, initUndistortRectifyMap

convertMaps(map1: Mat, map2: Mat, dstmap1: Mat, dstmap2: Mat, dstmap1type: number, nninterpolation: boolean): void;

2 available overloads

convertMaps(map1: Mat, map2: Mat, dstmap1: Mat, dstmap2: Mat, dstmap1type: number): void;

convertMaps(map1: Mat, map2: Mat, dstmap1: Mat, dstmap2: Mat, dstmap1type: number, nninterpolation: boolean): void;

map1

The first input map of type CV_16SC2, CV_32FC1, or CV_32FC2 .

map2

The second input map of type CV_16UC1, CV_32FC1, or none (empty matrix), respectively.

dstmap1

Output destination, filled by the native operation. The first output map that has the type dstmap1type and the same size as src .

dstmap2

Output destination, filled by the native operation. The second output map.

dstmap1type

Type of the first output map that should be CV_16SC2, CV_32FC1, or CV_32FC2 .

nninterpolation

Flag indicating whether the fixed-point maps are used for the nearest-neighbor or for a more complex interpolation.

Upstream declaration ↗

These signatures describe this package. Upstream documentation can mention optional backends that are absent from this build. Check runtime compatibility before choosing a backend or file format.