What's the fastest way to increase color image contrast with OpenCV in python (cv2)?

Question

I\'m using OpenCV to process some images, and one of the first steps I need to perform is increasing the image contrast on a color image. The fastest method I\'ve found so

Answer 1

Use the cv::addWeighted function. It's design to work on two images

dst = cv.addWeighted( src1, alpha, src2, beta, gamma[, dst[, dtype]] )

But if you use the same image twice AND you set beta to zero, you can get the effect you want

dst = cv.addWeighted( src1, alpha, src1, 0, gamma)

The big advantage to using this function is that you will not have to worry about what happens when values go below 0 or above 255. In numpy, you have to figure out how to do all of the clipping yourself. Using the OpenCV function, it does all of the clipping for you and it's fast.