OpenCV Python equalizeHist colored image

Question

I need to do a histogram equalization for a colored image.

First I convert the colored image to gray and give it to the equalizeHist function:

image = cv2.imread("photo.jpg")
image = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)
cv2.equalizeHist(image)
cv2.imshow("equalizeHist", image)
cv2.waitKey(0)

But after this I need to convert the image back to RGB; how can i do that?

Answer 1

Source : https://www.packtpub.com/packtlib/book/Application-Development/9781785283932/2/ch02lvl1sec26/Enhancing%20the%20contrast%20in%20an%20image

import cv2
import numpy as np

img = cv2.imread('input.jpg')

img_yuv = cv2.cvtColor(img, cv2.COLOR_BGR2YUV)

# equalize the histogram of the Y channel
img_yuv[:,:,0] = cv2.equalizeHist(img_yuv[:,:,0])

# convert the YUV image back to RGB format
img_output = cv2.cvtColor(img_yuv, cv2.COLOR_YUV2BGR)

cv2.imshow('Color input image', img)
cv2.imshow('Histogram equalized', img_output)

cv2.waitKey(0)

~edit: original link is no longer available, similar idea is implemented here: Histogram Equalization of a Color image with OpenCV