Photoshop
Chapter 3—Selection Tools Part 2
Lasso Tools
Instead of creating fixed-shape selections like the marquee selection tools, the lasso selection tools create free-hand drawn selections.
The Lasso Tool
Draws a selection beginning where you click the mouse and following the cursor as you drag the mouse. If you let go of the mouse button while selecting with this tool, PS automatically finishes the selection for you by drawing a straight line from the point where you release the mouse button to the starting point. For best results, zoom in so you can draw them as accurately as possible. Use the add to selection and the subtract from selection tools to clean up any mistakes.
The Polygonal Lasso Tool
Similar to the Lasso tool with the same options. The major difference is that the PLT creates only straight lines. Every time you click the mouse, you can change the direction and create another straight line segment. Good for rectangular or square shapes.
The Magnetic Lasso Tool
Finds the edge of objects in an image. Works well only if the area you want to select does not blend with the colors around it. Draws a selection where two contrasting colors meet. The MLT generates fastening points which hold the selection border in place. If it gets confused press Delete or Backspace as you backtrack the cursor. Click along key points such as curves where directions change rapidly.
The Options bar contains settings that control the tool’s sensitivity. Width: determines how wide of an area the tool analyzes while trying to find an edge. (If set at 10, it looks within an area of 10 pixels. Enter a high percentage in the Contrast setting if the area contrasts sharply with the background behind it. This makes it work more efficiently. A high number in the Frequency box means that fastening points will be created more frequently. This can be helpful when selecting an area that does not sharply contrast with the colors around it.
(Mention Keyboard Shortcuts, provided)
(Go through Tutorial 3-4, Part 2) have them stop at the end of the tutorial. Switch places
Magic Wand Tool
Allows you to click on a single pixel and have PS look for other pixels that are similar in color and select them as well. This helps you select complicated areas of similarly colored pixels such as blue sky showing through tree branches. But the area you want to select should contrast with the surrounding areas.
Options: Tolerance controls how tolerant the tool is of other colors. If low value is entered only colors that are very similar are chosen. If maximum value is entered (255), all pixels would be selected, no matter what color they are. Settings from 5-75 are most common.
Pixels that are touching each other are called contiguous. The tool will only select those pixels that touch each other. If not checked, those colors in the same pixel range would be selected from all over the image.
We will discuss layers in Chapter 4, but know for now that when Sample all layers is checked, the tool will select pixels on all visible layers. When unchecked, it will only choose the active layer.
The Select Menu
Contains commands that can adjust selections in many useful ways.
All=selects entire image. If several layers, only the contents of the active layer are selected. (Could select all and then use the subtract from image option)
Deselect=clears any selections in your image. Shortcut is Control-D, helpful because this is used often. (Some menus won’t let you use them if part of the image is selected, use this option)
Reselect=if you deselect an area, you can bring it back for later use. (Any time after de-selection but before new item is selected.)
Inverse=opposite of. (Sometimes its easier to select the part that you do not want to include first, and then invert the selection, ex. something with a white background)
Quick Mask Mode
Select an area in different ways. You use the brush tool, or other painting and drawing tools and various brush styles to paint a transparent color over your image. This creates a protective shield called a mask and is painted over portions of the file you do not want to select.
Choose Edit in Quick Mask mode from the toolbox. To create a selection in quick mask mode, select the brush tool choose a brush style and diameter and select black as the foreground color to pain the mask. Zoom in to paint the mask accurately. To erase parts of the mask, change the foreground color to white, then the brush tool will act as an eraser. When you have finished creating the mask, the entire image except for the areas that are covered by the mask are selected.
Horizontal Type Mask and Vertical Type Mask will allow you to make selections shaped like text. They are accessed by clicking on the Horizontal Type Tool and holding the mouse button until the other type tools appear in a pop-up menu.
Quick Selection Tool
Works like a paintbrush, but it does not apply any color. It selects whatever colors you “paint.” As you click and drag with this tool, it senses the colors you want to paint, creates a selection, and expands it automatically to include all similar colors nearby. Adjust the diameter of the brush picker.