About Selecting and Selection Tools in Adobe Photoshop CS5
Note: This excerpt does not include the lesson files. The lesson files are available with purchase of the book.
Making changes to an area within an image in Photoshop is a two-step process. You first select the part of an image you want to change with one of the selection tools. Then, you use another tool, filter, or other feature to make changes, such as moving the selected pixels to another location or applying a filter to the selected area. You can make selections based on size, shape, and color. The selection process limits changes to within the selected area. Other areas are unaffected.
The best selection tool for a specific area often depends on the characteristics of that area, such as shape or color. There are four types of selections:
Geometric selections The Rectangular Marquee tool () selects a rectangular area in an image. The Elliptical Marquee tool (), which is hidden behind the Rectangular Marquee tool, selects elliptical areas. The Single Row Marquee tool () and Single Column Marquee tool () select either a 1-pixel-high row or a 1-pixel-wide column, respectively.
Freehand selections Drag the Lasso tool () around an area to trace a freehand selection. Using the Polygonal Lasso tool (), click to set anchor points in straight-line segments around an area. The Magnetic Lasso tool () works something like a combination of the other two lasso tools, and works best when good contrast exists between the area you want to select and its surroundings.
Edge-based selections The Quick Selection tool () quickly “paints” a selection by automatically finding and following defined edges in the image.
Color-based selections The Magic Wand tool () selects parts of an image based on the similarity in color of adjacent pixels. It is useful for selecting odd-shaped areas that share a specific range of colors.