Removing Hair From Backgrounds
If you’ve ever had to remove a subject from its background using Photoshop, you probably know that the task is often easier said than done, especially if the subject has hair.
Whether the subject is a person or an animal, isolating it from its background while maintaining the integrity of the hair fibres is not always straightforward.
If you have watched tutorials online that show the process, notice how almost all of the tutorials use an image that has a remarkably clean background. The fact is that isolating strands of hair is not that simple when working with unclean backgrounds. Unclean backgrounds include those that are of a similar colour to the hair and/or have many different patterns.
The first tool I use is the Refine Edge assistant in the refine mask menu. Once I have made my selection with any number of tools (my favourites being magic wand and polygonal lasso), I go to the Select and Mask menu. In there, I will use Smart Radius and push the number up accordingly. Usually it will range from 1-8 when working with hair.
Once I have my settings appropriate, I will then use the refine edge brush and will mouse over the strands of hair. Depending on the colour contrast between the hair and background, this tool will work to your benefit or detriment.
If there is not enough contrast between the background and stray hair, the refine edge brush will undo fair portions of the edges that were previously selected for masking. To get around this, I exit the Select and Mask panel and add a temporary Levels adjustment layer to the image. I will adjust the levels drastically so there is a noticable difference in lighting between the background and hair in the foreground.
Once I have the high contrast values applied as a clipping mask, I then return to the Select and Mask panel to finish refining edges. Though it may not be perfect, this technique certainly helps in many instances.
Before I learned about refining edges, I learned how to use the Background Eraser tool. Of course, the tutorials I watched all had brilliant photos of models with large, flowing hair. However, they were all on solid backgrounds, oftentimes white or light blue. This made it easy to practice, but when I used the technique on more difficult projects, it was almost entirely useless.
The premise of using the Background Eraser tool is that you can toggle particular settings to select only sampled areas of background behind the strands of hair. It works beautifully on clean backgrounds, but does more harm than good on unclean backgrounds. You have to work with different tolerance levels to erase without damaging the hair, but if the tolerance is too low, then you won’t erase enough of the background.
Unless you’re using Photoshop for processing pictures from a hair photoshoot, then my methods might help.
I first use the Refine Edge tools and that often gets the job done for me. If I’m working with clean backgrounds, then Background Eraser tool is the first one I try and it works well enough and fairly quickly.
However, I know that unless I have a perfect background, I won’t get a perfect isolation. I accept that and instead work around these defects of processing.
My compositions will usually be arranged in such a way as to hide any blemishes or poor isolating jobs. That’s not admitting defeat, but working within one’s capabilities and time constraints.
Beyond simple positioning strategies, I will make use of adjustments that I use for photo retouching. If a subject has blonde hair and is on a brown background, then I will use Hue/Saturation to desaturate the background. After I might use Curves and Levels to blend that negative space in. It’s a process in itself and one I might use as a last resort, but with enough effort it can make a significant difference.