Computer Vision with OpenCV 3 and Qt5

Histogram equalization

The histogram of an image can be used to adjust the brightness and contrast of an image. OpenCV offers a function called equalizeHist that internally calculates the histogram of a given image, normalizes the histogram, calculates the integral of the histogram (sum of all bins), and then uses the updated histogram as a lookup table to update the input image's pixels, which leads to a normalized brightness and contrast in the input image. Here's how this function is used:

    equalizeHist(image, equalizedImg); 

If you try this function on images that have an out-of-place brightness level, or contract, then they will be automatically adjusted to a visually better level in terms of brightness and contrast. This process is ...