Ken Tough wrote:
Gaikokujin Kyofushso wrote:
Hi, I am trying to figure out how to realisticly change the color of hair in a photo. I would like to change this guys light brown hair to dark black (like Asian). I have played around with selective color adjusting, masking, etc but can’t seem to get the right effect. Any help would be greatly appreciated!
There are two issues – the one you seem to be having problems with is the most common one, the masking. There are several techniques for dealing with this. If you haven’t tried the Extract tool, now is the time. There is a good tutorial at www.myjanee.com, and Dr Brown at
http://www.russellbrown.com also has a good video tutorial.
Another method that works well if you have a contrasting color behind the hair is to use either the a or b channel of Lab as a mask – use levels to see which of the two is better. For that matter, check all the channels: r,g,b,c,m,y,k,l,a, and b for the best mask, remembering that you have any number of cmyk channels depending on your gcr / ucr settings. The curvemeister demo is a fast source for these channels, using the copy channel command, which is 100% functional in the demo.
Another technique is to painstakingly paint the mask – this is done often for glossy ads, and although great skill is required, it remains the best, final, way to get a mask.
Once you have your mask, the second problem is getting realistic colors. Brown hair has warm highlights. Black hair, particularly Asian hair, has cold highlights. Getting this to look "realistic", as you say, is probably going to be even more difficult than the original mask, but requiring an aesthetic judgement rather than technical expertise.
Which is why some have suggested that you take a more direct approach of cloning hair from another image. Or pose someone with hair similar to what you want, pick a contrasting background, duplicate the lighting, and simply add the hair in a single operation. This seems like a lot of work, but in the end it will be easier, and yield a much more convincing result. —
Mike Russell
www.curvemeister.com
www.geigy.2y.net