Clipping a subject from the background of an image is a fairly straightforward process that allows you to change the background or move the subject to a new image. There are numerous ways to do this and tools to use. Here’s my preferred method for clipping a subject from a background in Photoshop.
Step 1: Shooting The Subject
If at all possible, start by shooting the subject to be cut out against a solid, seamless background. Background detail at the edges of the subject makes it more difficult to make a clean selection. Better still, if you’re able to shoot with the composite in mind, try to approximate the color of the new background they’ll be dropped onto. This will make it easier to hide the last remaining pixels that are likely to cling to the edges of the subject when you make the mask and to allow for any reflections that appear on the subject—on the shine of shoes, for instance, or on eyeglass frames—to more seamlessly match the new background.
Step 2: Selecting The Subject
With the subject photo opened in Photoshop, start by copying the image onto a new layer (by clicking CTRL-J on Windows or Command-J on a Mac) to duplicate the image layer. Then, choose your favorite selection tool to grab as many pixels as possible in as few clicks as possible. This could be the magic wand, or the lasso tool, or even a color range selection. But I always start with Select Subject found under the Select menu. Use any and all of these selection tools in combination to build the perfect selection and finish up by using the lasso tool to make manual fine-tuning adjustments as needed. Shift-click adds to the selection, option-click subtracts.
Step 3: Use The Refine Edge Tool
Hold the shift key while clicking on the Select and Mask menu item to open up the original—and in my opinion, much preferred—version of Photoshop’s Refine Edge tool, which is still there but hidden in the menu. There’s lots of control to be had in Refine Edge, including adjusting the radius of the edge and the amount of smoothing applied to the selection. The two adjustments I find most useful in the Refine Edge palette, though, are the Feather slider and the Shift Edge slider. If your selection appears too fuzzy when the layer mask is ultimately applied, it’s likely got too much feathering here. Dial it back to find a crisper, sharper edge selection that’s especially useful around fine detail such as hair and foliage.
The Shift Edge slider will automatically expand or contract the edge selection, which I find to be most useful for eliminating ghosting around the outside of the selection. Dial down the Shift Edge slider to, say, 25 percent and it will typically contract just enough to tighten up the selection and hide any remaining background ghosting on the edge. When you’re finished refining the edge, click the Output To dropdown and choose the Layer Mask option to mask away the background and reveal the isolated subject. To better see how effective your selection has been, choose a contrasting color and fill an empty layer below. This layer can later be deleted or deactivated in the finished image.
Step 4: Further Refine The Edge By Hand
The final step is to further refine the edge by hand if any ghosting of the background is visible around the subject, for instance. My preferred approach is to select only the edge and then mask it away. To do this, command-click on the mask in the layers palette to load the outline as a selection. Then, under the Select menu choose Contract and dial in a minor change of just one or two pixels, then click Okay. This will contract the selection so that when inverted you’ll be left with just a selection of the edge. Click inverse under the Select menu and then choose a dark gray or black color to paint into the mask along the edge of the selection (taking care to ensure the mask is active before painting). For additional adjustment beyond the edge of the mask, choose a paintbrush and adjust its diameter and edge sharpness to match the nature of the edge, then click and drag to paint away the mask—using black where you want to hide the contents and white to reveal the detail where you want it.
With the subject finally perfectly isolated, the layer mask can be applied to make the image cut and paste-able onto a new image or paste a background into the image on the layer below. Another approach is to deactivate all of the background layers below the subject and then save the file as a PNG in order to preserve the transparency in the image file, which can be added to any number of different backgrounds or even used digitally in applications where the background designs needs to show through.