How to Transform Layers in Photoshop CS6
When compositing multiple images in Photoshop CS6, you’ll no doubt have to transform layers in your image to fit it into your layout. Fortunately, Photoshop makes scaling an easy chore by providing you with the Transform and Free Transform commands on the Edit menu.
Transforming layers is almost identical to transforming selections, except that you don’t need to make a selection first. After an element is on a layer, you can just choose the appropriate transformation command and off you go. Additionally, you can apply a transformation to multiple layers simultaneously if you select the multiple layers first.
Try to perform all your transformations in one execution. Each time you transform pixels, you’re putting your image through the interpolation process (increasing, decreasing, or remapping pixels). Done repeatedly, your image may start to turn into mush. Either way, it won’t be as pristine as it was before. The only exception is for flips and rotations that are a multiple of 90 degrees. These are harmless.
Note that Photoshop displays your dimensions on-image as you size your transform box. This is another benefit of Adobe’s commitment to supporting rich cursors — cursors that not only do the job but give you additional tool information.
If your image looks jagged after you transform it, you may have your preferences set incorrectly for your interpolation method. Choose Edit→Preferences→General (Photoshop→Preferences→General on the Mac) and select the Bicubic Automatic from the Image Interpolation pop-up menu. Bicubic Automatic will automatically detect whether you are trying to upsample (enlarge) or downsample (reduce) your image and will choose the appropriate algorithm.
When the Move tool is active, you can transform a layer without choosing a command. Simply select the Show Transform Controls option on the Options bar. This option surrounds the contents (or an active selection) of the layer with a bounding box with handles. Drag these handles to transform the contents.