Selecting

About selecting pixels 

A selection isolates one or more parts of your image. By selecting specific areas, you can edit and apply effects and filters to portions of your image while leaving the unselected areas untouched.

Photoshop provides separate sets of tools to make selections of raster and vector data. For example, to select pixels, you can use the marquee tools or the lasso tools. You can use commands in the Select menu to select all pixels, to deselect, or to reselect. 

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. 

Selections can be copied, moved, and pasted, or saved and stored in an alpha channel. Alpha channels store selections as grayscale images called masks. A mask is like the inverse of a selection: it covers the unselected part of the image and protects it from any editing or manipulations you apply. You can convert a stored mask back into a selection by loading the alpha channel into an image.

 

Select, deselect, and reselect pixels 

You can select all visible pixels on a layer or deselect any selected pixels. 

 If a tool is not working as expected, you may have a hidden selection. Use the Deselect command and try the tool again.

Select all pixels on a layer within the canvas boundaries

1. Select the layer in the Layers palette. 
   
2. Choose Select > All. 
   

Deselect selections

  Do one of the following:

• Choose Select > Deselect.

If you are using the Rectangle Marquee tool, the Elliptical Marquee tool, or the Lasso tool, click anywhere in the image outside the selected area          

Select with the Lasso tool 

The Lasso tool is useful for drawing freeform segments of a selection border. 

1. Select the Lasso tool , and select options. 
   
2. Drag to draw a freehand selection border. 
   
3. Specify one of the selection options in the options bar. 
4. (Optional) set feathering and anti-aliasing in the options bar. See Soften the edges of selections. 
   
5. To draw a straight-edged selection border when no other pixels are selected, press Alt (Windows) or Option (Mac OS), and click where segments should begin and end. You can switch between drawing freehand and straight-edged segments. 
   
6. To erase recently drawn segments, hold down the Delete key until you’ve erased the fastening points for the desired segment. 
   
7. To close the selection border, release the mouse without holding down Alt (Windows) or Option (Mac OS). 
   
8. (Optional) Click Refine Edge to further adjust the selection boundary or view the selection against different backgrounds or as a mask. See Refine selection edges.