Chapter fourth and fifth

Objectives are :

• Create elliptical and rectangular selections
• Identify the specific function of various lasso tools
• Combine selections
• Remove portions of a selection
• Save and load selections
Selection Tools
•Selections are used to specify areas of editing within an image, such as color changes or replacing a sky.
The Options bar contains options for changing:
  •  Selection behavior
  •  Feathering
  •  Aliasing

Creating Elliptical And Rectangular Selections 

•Holding the mouse button over a Marquee tool icon reveals the Alternate tools available.
•Dragging with the Marquee tool will create an area outlined by “marching ants” or “dotted lines” that let you know what area has been selected.
•By setting a Fixed Aspect Ratio, it will “lock” your selection to a specific ratio.
Adding and Removing Parts of a selection
•Choose the Add to Selection button on the options bar before creating a new selection to add to the selected area.
•The “Add to Selection” button lets you add a new selected area to the image.
•Select>Inverse selects the unselected areas of the image and deselects the selected areas of the image.
Using Feather
By using Feather you can soften the edges of a selection 
and short cuts are :
  • M toggles the Rectangular and Elliptical Marquee tools
  • Command/Control-I inverses a selection
  • Command/Control-D deselects a selection
  • Command/Control-H hides the marching ants

Using Lesso Tools :

  • Polygonal Lasso tool creates straight sided selections around objects by clicking the objects edges.
  • Magnetic Lasso tool tracks the edges of an objects based on shifts in color or tone.
  • Lasso tool creates selections based on freehand tracing.

Transforming Selections includes 

Scale that changes the size of a selection,Rotate,Skew/Distort,Perspective,filiping.

Saving and Loading selections 

•Choose Select > Save Selection to save a selection
•Selections are saved as Alpha Channels
•Channels also contain specific image data:
  • Black and White images contain one color channel
  • An RGB image contains 4 color channels
  • A CMYK image contains 5 color channels