Color Correction in Photoshop
Correcting a screwed up photo is quite easily done with photoshop. All we need is just some fundamental knowledge of what colors in numbers mean.
Take a look at this photo, taken by a friend of mine.
It’s quite obvious the yellows are overpowering the entire photo. In post production, we often need to restore images to their local colors before other artistic decisions can be made, like grading etc.
This is actually quite simple to achieve. We just need to identify a part of the photo that is neutral in color, which means that it is grey (black to white), and in terms of numbers, red/green/blue values have to be the same. In photoshop, there is the sampler info tool that we can use to sample a part of the photo and find out the RGB values. I chose the pillars, and set the sampler to read 5px instead of 1px because there are noise in the photo. Then all we need is to use the curve adjustment and pull the channels (in this case, blue) to make the values meet. Be careful not to overdo it and lose data, which will happen if our curve gets flattened to 0.
Here is the final image, after some cleaning up and color dodge.
Image courtesy of Joel Lau.