How can I white balance an image based on part of the image I know is white?

I have this image, and I know that the top left of it should be white. Is there a way for me to select that part of the image and say it's white, and then adjust the color of the rest of the image to match?

What I have so far is using roipoly to select the part of the image that I want, but I have no idea where to go from there in regards to color correction.

Answer 1

[Mahmoud Afifi]

Try this one:

http://130.63.97.192/WB_for_srgb_rendered_images/demo.php

Reference: When Color Constancy Goes Wrong: Correcting Improperly White-Balanced Images, CVPR'19.

http://openaccess.thecvf.com/content_CVPR_2019/papers/Afifi_When_Color_Constancy_Goes_Wrong_Correcting_Improperly_White-Balanced_Images_CVPR_2019_paper.pdf