Image Selection in Photoshop

Image Selection

There are separate sets o tools to make selections of bitmap and vector data. For example, to select bitmap pixels, you can use the marquee tools or the lasso tools.

To select vector data, you can use the pen or shape tools, which produce precise outlines called paths. You can convert paths to selections or convert selections to paths.

Using the Select Menu:

You can use many commands in the Select menu to select all pixels, to deselect or to reselect.

Select all pixels on a layer within the canvas boundaries:

1)      Select the layer in the Layers palette.

2)      Click on Select menu > All.
Select > All selects the entire document.

Deselect Selections:

a)      Click on Select menu > Deselect.

If you're done using a selection and would like to work on the entire image, choose Select > Deselect. When you don't have a selection, you can work on the entire image.

Reselect selection:

Click on Select menu > Reselect.
If you need to use the last active selection (and there isn't a selection on your screen), you can choose Select > Reselect. This is great when you need to use the same selection over and over again.

Inverse

As you might expect, the Inverse command selects the exact opposite of what you originally selected. If, for example, you have the background of an image selected, after choosing Select > Inverse, you'll have the subject of the image selected instead.

Selection by Marquee tools:

The marquee tools let you select rectangles, ellipses, rounded rectangles and 1-pixel rows and columns. By default, a selection border is dragged from its corner.

1.   Select a marquee tool:

a.       Rectangle Marquee to make a rectangular selection.

b.      Elliptical Marquee to make an elliptical selection.

c.       Single Row or Single Column Marquee to define the border as a 1-pixels-wide row or column.

2.    In the options bar, specify whether to add a new selection, add to a selection, subtract from a selection or select an area intersected by other selections.

3.  Specify a feathering setting in the options bar. Turn anti-aliasing on or off for the Rounded Rectangle tool or the Elliptical Marquee tool.

4.     For the Rectangle tool, the Rounded Rectangle tool, or the Elliptical Marquee tool, choose a style in the options bar:

1)      Normal to determine marquee proportions by dragging.

2)   Fixed Aspect Ratio to set a height-to-width ratio. Enter values (decimal values are valid in Photoshop) for the aspect ratio. For example, to draw a marquee twice as wide as it is high, enter 2 for the width and 1 for the height.

3)      Fixed Size to specify set values for the marquee’s height and width. Enter pixel values in whole numbers.

4)    Keep in mind that the number of pixels needed to create a 1-inch selection depends on the resolution of the image.