equalizeHist

Image processingfunctionOpenCV 5.0.0

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

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

Explore visually: Histogram equalization →

Redistribute grayscale intensities using their cumulative histogram.

VISUAL WALKTHROUGHColour

REFERENCE INPUTNarrow intensity range

The same scene stays here while the working view changes.

→

RESULTRedistributed intensities

Applying the monotone mapping stretches the occupied range and makes the objects easier to distinguish.

Computed teaching example on a 24 × 16 image. Small kernels and simplified settings keep each change visible; use the image laboratory for native OpenCV.

Equalizes the histogram of a grayscale image.

The function equalizes the histogram of the input image using the following algorithm:

• Calculate the histogram H for src .
• Normalize the histogram so that the sum of histogram bins is 255.
• Compute the integral of the histogram:

H'_i =  \sum _{0  \le j < i} H(j)

• Transform the image using H' as a look-up table: \texttt{dst}(x,y) = H'(\texttt{src}(x,y))

The algorithm normalizes the brightness and increases the contrast of the image.

equalizeHist(src: Mat, dst: Mat): void;

src

Source 8-bit single channel image.

dst

Output destination, filled by the native operation. Destination image of the same size and type as src .

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.