I was provided an image file, which is a photo of a painting; unfortunately, the photo is not of the best quality, and shows glare. How can I "deglarify" the image? I do not have Photoshop, but I do have Paint.net and Irfanview.
Here is the image:
A friend of mine was able to improve it, like so:
This is actually a "punified" version, as his file was 2MB and too large to upload here.
I don't know exactly which magic wands he waved, but it definitely looks better!
The short answer is: you can't.
I have taken photos of 1000's of paintings and you simply will never get rid of the glare without influencing the fidelity of the reproduction of the painting. You can use "dodging and burning tools" (the old-fashioned terms), but the details are not there and it rarely results in something presentable. Most image editing programs have these tools.
If this is not possible, the next best thing to try is to take two photos where the glare is only visible in one half of each image (but opposite halves), carefully correct each image for shape (square them off) while perfectly aligning the details in them, and then add a mask to the one on top such that you only get the best part of each photo.
The best way to take a photo of a painting (without a pro studio and really good lights that are far away) is to use a polarized filter and polarized light sources, and then make color/saturation adjustments to correct for the polarizer's influence.
If this is for a book, get someone to take a proper shot of it. Anything less is a waste.
You still may be able to nail it if you get into contact with someone who has another photo. If that really is another photo of the same painting, you probably have glares at different places. By combining the two, much more glareless area may be resulted. I have done it for one artist who fortunately had himself understood to take several photos from different angles just for trying to find a low glare shot. In his case the glares were quite easy - only a limited area for each photo.
