Photoshop’s standard selection tools, the Marquee, Lasso and Magic Wand, are fine for making basic selections of regular, well defined shapes, but they’re not so good at picking out soft-edged or very fine shapes. One thing in particular that has always been a problem is the edge of fine or untidy hair.
Take the photo above for example: This model has been photographed in a typical studio setting, with good lighting and against a plain light grey background. Photos like this are used all the time for catalogues, advertising posters and the like. However, in order to fit these needs the model will have to be separated from the background. With a plain background like this, it would be tempting to use a normal selection tool such as the Magic Wand.
However if we try it, what we end up with is just not usable.
The edge around the model’s hair will look terrible. The automatic Magic Wand selection has produced a very jagged edge, because it can’t distinguish between the fine edge of the hair and the background. Fortunately the latest version of Photoshop has a feature called Refine Edge, which is capable of making much finer distinctions.
Refine Edge is very easy to use. Starting with a Magic Wand or Polygonal Lasso selection as close as possible to the edge of the hair or any other soft edge, click on the Refine Edge button on the tool options bar.
In the dialog window that opens, in Edge Definition, check the box marked Smart Radius, and use the square brackets keys to set the brush size so that it’s large enough to cover the hazy edge area around the hair. Then simply paint around the edge, overlapping both the model and the background.
When you’ve been around all the edge area that you want to refine, click OK, and then wait a few seconds while the program recalculates the edge. What you will then see is that the result is a good improvement over the first attempt.
Photoshop has other tools to modify a selection which you’ll find, appropriately enough, in the Select menu, under Modify. The options include Border, Smooth, Expand, Contract and Feather. They’re all relatively simple, but useful nonetheless.
Border – Border converts the single-line selection into a border of the specified width. You can use this selection to create a border around your selection by using the Paint Bucket tool.
Smooth – Smooth removes the kinks and wrinkles from the line of your selection. It’s useful when you’re selecting smooth-edged objects, but it will round off the corners of any irregular shapes.
Expand – Expand, as the name suggests, expands the size of the selection by the specified number of pixels.
Contract – Contract is the opposite of Expand. It shrinks the size of the selection by the specified number of pixels.
Feather – Feather softens the edge of the selection by the radius set in the dialog box. It’s perhaps the most useful option here, particularly if you’re trying to copy and paste the selection into a background.