HoughLinesP

Image processingfunctionOpenCV 5.0.0

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

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

Explore visually: Hough line detection →

Let edge pixels vote for lines in a parameter space.

VISUAL WALKTHROUGHGeometry

REFERENCE INPUTEdge observations

A supported shape is mixed with a few unrelated edge samples.

→

RESULTRecover a supported line

The recovered geometry follows the consistent observations; isolated samples do not define the final shape.

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

Finds line segments in a binary image using the probabilistic Hough transform.

The function implements the probabilistic Hough transform algorithm for line detection, described in [Matas00]

See the line detection example below:

This is a sample picture the function parameters have been tuned for:

And this is the output of the above program in case of the probabilistic Hough transform:

See: LineSegmentDetector

HoughLinesP(image: Mat, lines: Mat, rho: number, theta: number, threshold: number, minLineLength: number, maxLineGap: number): void;

3 available overloads

HoughLinesP(image: Mat, lines: Mat, rho: number, theta: number, threshold: number): void;

HoughLinesP(image: Mat, lines: Mat, rho: number, theta: number, threshold: number, minLineLength: number): void;

HoughLinesP(image: Mat, lines: Mat, rho: number, theta: number, threshold: number, minLineLength: number, maxLineGap: number): void;

image

8-bit, single-channel binary source image. The image may be modified by the function.

lines

Output destination, filled by the native operation. Output vector of lines. Each line is represented by a 4-element vector (x_1, y_1, x_2, y_2) , where (x_1,y_1) and (x_2, y_2) are the ending points of each detected line segment.

rho

Distance resolution of the accumulator in pixels.

theta

Angle resolution of the accumulator in radians.

threshold

%Accumulator threshold parameter. Only those lines are returned that get enough votes ( >\texttt{threshold} ).

minLineLength

Minimum line length. Line segments shorter than that are rejected.

maxLineGap

Maximum allowed gap between points on the same line to link them.

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.