Adobe Photoshop CS5 for Photographers - Martin Evening [207]
If you want to achieve a more aggressive smoothing you can combine adjusting the Feather and Contrast sliders. Simply increase the Feather slider to blur the mask and then increase the Contrast to get back to the desired edge sharpness.
The Shift Edge slider is like a choke control. It works on the mask a bit like the Maximum and Minimum filters in Photoshop. You can use this slider to adjust the size of the mask in both directions, making it shrink or expand till the mask fits correctly around the object you are masking. I usually find that the Shift Edge slider is the one I find the most useful for adjusting the selection/mask shape, followed by the Feather and Contrast sliders when I wish to refine the mask further.
Refine Edge output
Lastly, we have the new Output section, which determines how the masked image layer blends with the image layers below it. This is a crucial component to successful masking, which can so often fail when the pixels around the outer edges of a mask (picked up from the original background) don't match those of the new background. Whenever you need to successfully blend a masked image layer with the other layers in a new image, you can check the ‘Decontaminate Colors’ option. You can then adjust the Amount slider in order to remove any of the last remaining background colors that were present in the original photo (see Figure 9.28). The best advice here is to only dial in as much decontamination as is necessary in order to achieve the most detailed and smoothestlooking blend.
Figure 9.28 Here you can see a close-up comparison between a Refine Edge edited masked layer (top) and below that, one where the ‘Decontaminate Colors’ option was switched on to hel improve the blend between the masked layer and the pixels in the layer below.
The ‘Output To’ section (Figure 9.29) allows you to output the refined selection in a variety of ways, either as a modified selection, as a layer mask, as a new layer with transparent pixels, as a new layer with a layer mask, or as a new document: either with transparent pixels or with a layer mask.
Figure 9.29 This shows the Output To menu options for the Refine Edge dialog.
Quick selection brush settings
The quick selection brush settings are the same as for the other paint tools, except adjusting the brush hardness and spacing won't really have any impact on the way the quick selection tool works. If you are using a pressure sensitive tablet it is worth checking that the Pen Pressure option is selected in the Size menu, as this allows you to use pen pressure to adjust the size of the quick selection tool brush (see Figure 9.30 below).
Figure 9.30 This shows the quick selection tool brush settings where the Pen Pressure option has been selected from the Size menu. This links the quick selection tool cursor size to the amount of pen pressure applied.
Working with the quick selection tool
The quick selection tool is grouped with the magic wand in the Tools panel. It is a more sophisticated kind of selection tool compared with the old magic wand and has some interesting smart processing capabilities. You can use the quick selection tool to make a selection based on tone and color by clicking or dragging with the tool to define the portion of the image that you wish to select. You can then keep clicking or dragging to add to a selection without needing to hold down the key as you do so. You can then subtract from a quick selection by holding down the key as you drag. What is clever about the quick selection tool is that it remembers all the successive strokes that you make and this provides stability to the selection as you add more strokes. So as you toggle between adding and subtracting, the quick selection temporarily stores these stroke instructions to help determine which pixels are to be selected