opencvjs equalizeHist

In OpenCV.js, the `equalizeHist` function is used to perform histogram equalization on an image using JavaScript. It is part of the OpenCV library and can be used to enhance the contrast of an image. Here is an example of how to use it:

// Load the image
let src = cv.imread('inputImage');

// Convert to grayscale
let gray = new cv.Mat();
cv.cvtColor(src, gray, cv.COLOR_RGBA2GRAY);

// Apply histogram equalization
cv.equalizeHist(gray, gray);

// Display the result
cv.imshow('outputCanvas', gray);
cv.waitKey();

In this example, we first load an input image using `cv.imread`. Then we convert it to grayscale using `cv.cvtColor`. After that, we apply histogram equalization using `cv.equalizeHist` on the grayscale image. Finally, we display the result using `cv.imshow` and wait for a key press using `cv.waitKey`.

Make sure you have the OpenCV.js library properly included in your HTML file before using this code.