Selecting Hair and Fine Detail in Photoshop
from Photoshop Masking & Compositing
by Katrin Eismann
It would make my life a lot easier if all the portrait photographs I work with had an evenly lit, texturefree, contrasting background -- but life has a tendency to be complex, and our snapshots reflect that.
We'll begin with a classic snapshot of a happy mother with an even happier baby, standing in front of the family car. The challenges of this image are threefold --
* a busy background,
* a lack of contrast between the subjects' hair and
* the dark background, and the mother's fly-away hair.
All of these factors make this a challenging, yet not impossible, mask to make. Rather than thinking about all the problems it presents -- try thinking in black and white about separating image elements from one another to gracefully solve this challenge.
Selecting Hair and Fine Detail
The original photograph captures a candid moment. In the following example, we will use a Channel Mixer Adjustment Layer and layer blending modes to boost contrast while maintaining edge detail. The idea is to quickly create as much contrast as possible and then use the fill and painting tools to refine the details. In the process, you'll add a number of nondestructive production layers to build up the mask. Finally, we'll take the family on a trip to a park and use the Lens Blur filter to defocus the trees, as shown above, left.
Simplifying the background subliminally encourages the viewer to concentrate on the people in the picture.
Building the Initial Mask
1. Open the Channels palette and look at the individual channels. You can do this by clicking on each channel name or using (Cmd + 1, Cmd + 2, Cmd + 3) [Ctrl + 1, Ctrl + 2, Ctrl + 3]. Look for the channels with the most contrast and the smoothest tonality. In this image, both the red and the green channels contain contrast (figure 8.17) that we can take advantage of and accentuate to make a mask. Click RGB or (Cmd + ~) [Ctrl + ~] to return back to the color image.
figure 8.17 Look for the channel with the most contrast and smoothest tonal range.
2. To apply the "thinking in black and white" approach, add a Channel Mixer Adjustment Layer, select the monochrome box, and move the red and green sliders to the right. In this instance, I used the extreme values of +100 for red and +132 for green.
figure 8.18 To increase the difference between dark and light, use the Channel Mixer Adjustment Layer.
3. To push the contrast even higher, take advantage of layer blending modes, which impact how the layers interact. The contrast-enhancing group is the largest group, beginning with Overlay. In this case, choose Hard Light as shown in figure 8.19, which screens the lighter areas, making them lighter, and multiplies the darker values, making them darker.
figure 8.19 Changing the Layer blending mode increases the contrast even more.
