Adobe 13101332 User Guide - Page 166

Adobe Photoshop Help Using Help | Contents | Index Selecting Back 166 The Border command creates an anti-aliased selection. (See "Softening the edges of a selection" on page 166.) To paint a hard-edged border around a selection, use the Stroke command. (See "Filling and stroking selections and layers" on page 249.) To expand a selection to include areas with similar color: Do one of the following: • (Photoshop) Choose Select > Grow to include all adjacent pixels falling within the tolerance range specified in the magic wand options. • Choose Select > Similar to include pixels throughout the image, not just adjacent ones, falling within the tolerance range. To increase the selection in increments, choose either command more than once. Note: You cannot use the Grow and Similar commands on images in bitmap mode. To clean up stray pixels left inside or outside a color-based selection: 1 Choose Select > Modify > Smooth. 2 For Sample Radius, enter a pixel value between 1 and 100, and click OK. Photoshop or ImageReady checks around each selected pixel to find any unselected pixels falling within the specified range. For example, if you enter 16 for the sample radius, the program uses each pixel as the center of a 33-by-33-pixel area (16 pixels in the horizontal and vertical directions). If most pixels in the range are selected, any unselected pixels are added to the selection. If most pixels are unselected, any selected pixels are removed from the selection. Note: The relationship between physical distance and pixel distance depends on the resolution of the image. For example, 5 pixels is a longer distance in a 72-ppi image than in a 300-ppi image. (See "About image size and resolution" on page 62.) Softening the edges of a selection You can smooth the hard edges of a selection by anti-aliasing and by feathering. Anti-aliasing Smooths the jagged edges of a selection by softening the color transition between edge pixels and background pixels. Since only the edge pixels change, no detail is lost. Anti-aliasing is useful when cutting, copying, and pasting selections to create composite images. Anti-aliasing is available for the lasso, polygonal lasso, magnetic lasso, rounded rectangle marquee (ImageReady), elliptical marquee, and magic wand tools. (Select a tool to display its options bar.) You must specify this option before using these tools. Once a selection is made, you cannot add anti-aliasing. Feathering Blurs edges by building a transition boundary between the selection and its surrounding pixels. This blurring can cause some loss of detail at the edge of the selection. You can define feathering for the marquee, lasso, polygonal lasso, or magnetic lasso tool as you use the tool, or you can add feathering to an existing selection. Feathering effects become apparent when you move, cut, copy, or fill the selection. Using Help | Contents | Index Back 166