Selecting Squares and Circles on a Digital Image

Geometric selections — rectangular and oval-shaped regions — work well if you're preparing to make an adjustment or apply a fill to a large area and don't mind if the area doesn't follow the shapes within your image. You can select a square area and apply paint to it to create a frame around the central images in a figure.

Before shape tools were added to most image editing applications, using the Marquee selection tools was the only way to map out an area and fill it with color — creating solid-filled squares, rectangles, circles, and ovals. Most applications come with shape-drawing tools now, letting you draw just about any geometric shape or symbol (hearts, arrows, and so on) and then fill them with color. This strips the Marquee tool of one of its original jobs, but it remains an important weapon in your image editing arsenal.

Using the Marquee selection tools

To use the Marquee or geometric selection tools, simply click the tool and drag from the upper or lower corner of the desired selected area and diagonally away from that starting point. The farther away you drag, the bigger the selection becomes. The distance and angle from the starting point dictates the selection's size and proportions.

Selecting perfect squares and circles

If you want to select a square or circle instead of a rectangle or oval (often called an ellipse), you can add keystrokes to the process. In most image editors, holding down the Shift key while you drag the Marquee or other geometric selection tool creates a perfect square — if you're using the Rectangular Marquee tool. If you're using the Elliptical Marquee, holding down the Shift key selects a perfect circle. Paint Shop Pro offers a set of selection options, as you can see in Figure 1, in which the Freehand Selection tool is chosen. If you prefer a rectangular selection instead, you can use the drop-down list within the Tool palette to select a square or circle rather than a rectangle or an ellipse. You can also select rounded-corner rectangles in Photoshop, Elements, and Paint Shop Pro.