Click and drag the crosshairs across your image. A rectangular marquee should appear, with one corner where you started dragging and the opposite corner where you stopped. The red arrow in the picture (right) shows the movement of the cursor.There are four main ways to select areas of the image:
You can also select areas of the screen using the Pen tool or the Quick Mask function, but those are more advanced techniques that will be addressed later.
First open a stored image, then click on the Marquee tool. When your cursor is over the image, it should look like a thin plus sign. The center of the plus sign (or crosshairs) is the selection point.
Click and drag the crosshairs across your image. A rectangular marquee should appear, with one corner where you started dragging and the opposite corner where you stopped. The red arrow in the picture (right) shows the movement of the cursor.
Holding down the Alt key while dragging makes the marquee open outward with the starting point as the center, rather than a corner. This is shown by the red arrow in the picture (below).
Holding down the Shift key while dragging forces the marquee to be a perfect square. Shift + Alt combines the effects of both keys and makes the square open from the center point.
After you have selected an area of the image with the Marquee tool, the cursor changes its appearance to look like a small marquee with an arrow when held over the selected area. This cursor affects only the marquee itself.
Clicking anywhere in the image will make the marquee disappear, deselecting the area. If you click and drag inside the selected area, you can move the marquee's position to select a different place on the image. You can also move the marquee by using the arrow keys.
Look at the top of the screen, directly beneath the main menu bar. You should see the Marquee menu.
First look at the area beneath the number 1 in the picture (above). This determines the properties of the selection area. The default is that you can only select one area at a time with the Marquee tool. If you try to select a second area, the first marquee will disappear, to be replaced by the second one.
If you click on the second icon in this section, which shows two overlapping squares, it allows you to select multiple areas. Each successive marquee will add its area to the previous ones. They can be either contiguous or non-contiguous.
The third icon in this section allows one area to subtract from another. After you have selected an area, click on this icon. Select another area overlapping the first, and the new selection area will be subtracted from the first. These "subtraction" areas must overlap the initial selection. If you try to select an area outside the portion surrounded by the marquee, nothing will happen.
The fourth icon selects only the junction between two selection areas. Select part of your image and then click on this icon. Select an overlapping part of the image, and only the area where the two selections overlapped will remain selected. Selecting on an area that does not overlap will give you a warning message and deselect everything.
Now look at section two, "Feather." This allows the edge of your selection area to be gradual rather than sharp. The higher the number you enter in this box, the more the edge is blurred.
The box under the number three will only be active if you use the Elliptical Marquee explained below. Anti-aliasing is a process that smooths out edges gradually. If you have a high resolution image, it is probably a good idea to leave this box checked, because the smoothness will look more pleasing. However, if you are doing low-resolution work, or if you want a cleaner, sharper edge, uncheck this box.
Section four alters the properties of the marquee. The default style, "Normal," allows you to determine the width and height of the marquee separately as you drag. If, however, you change this style to "Fixed Aspect Ratio," you can form a marquee that has the width and height set at a constant proportion. You determine this proportion by typing the ratio in the "Width" and "Height" fields in section five.
If, instead of dragging the marquee to the desired size, you wish to determine the size of the marquee by a specific width and height, change the style to "Fixed Size." You can then input the width and height that you need in the section five fields.
Return to the tool bar. Click and hold on the Marquee tool. A menu will appear showing you different types of Marquee tools that are available. Click on the second option, the Elliptical Marquee tool.
This tool allows you to select round or elliptical areas. The commands work exactly the same as for the Rectangular Marquee tool. For example, holding the Shift key while dragging will select a perfect circle, as in the picture (right).
The Marquee tool is extremely useful, but sometimes you need to select an irregular area that can't be done with plain rectangles or ellipses. In this case, you will want to use the Lasso tool. Click on the Lasso icon in the tool bar. Your cursor will look like the loop of a lasso. The dangling tip of the rope is the selection point.Click and drag to encompass an area of your image. As soon as you let go of the mouse button, the final point will automatically connect itself in a straight line with the starting point to form a closed loop. This loop is your selection area.
You can use the Lasso tool to surround an object that you want to separate from the background, as in the picture (right). The Lasso tool also has a menu bar (below), similar to the menu for the Marquee tool.
Using the addition, subtraction, and overlap functions of the Lasso tool, you can alter and fine-tune your selection area, as in the picture (below).
As with the Marquee tool, the Lasso tool also has different types. You can see the choices by clicking and holding on the Lasso icon in the tool bar, as shown in the picture (below, right).
The second choice on the list, the Polygonal Lasso tool, allows you to create a selection area by clicking in various places on the image instead of dragging. Each place that you click forms a corner of a polygon. The corners are automatically connected by straight lines. You can close the loop of the polygon either by clicking on the starting point or by double clicking.
With the Magnetic Lasso tool, the computer assists you in placing the outline of the selection area. It uses clues such as differences in color or brightness to recognize the outline of the object you are trying to select, and the selection area is "magnetically attracted" to this outline. With this tool, you don't have to worry about having a steady or precise hand, because the computer does the work of remaining true to the outline on your behalf.
The drawback, however, is that if the outline of the object fades into the background, the computer can't tell the difference and the "magnetic" effect doesn't work properly. You may have to use the addition or subtraction properties to clean up the resulting selection area to your satisfaction.
Click on the Magic Wand icon in the toolbar. Your cursor will now look like a wand. The sparkly tip of the wand is the selection point. Click the wand on the image, and it will select an area of the same or similar color as the point that you touched.
Look at the Magic Wand menu. Just like the Marquee and Lasso tools, it also has addition, subtraction, and overlap modes. However, it has a new property: "Tolerance." The tolerance tells the computer how similar in color a neighboring pixel must be in order to be selected. A low tolerance means that the computer is very discriminating and the color must be almost exactly the same. A high tolerance means that the computer's judgment is looser and the color can be somewhat different. The pictures below illustrate clicking on the same point with different tolerance levels.
 Tolerance: 10 |
 Tolerance: 25 |
 Tolerance: 50 |
Note in the Magic Wand menu that the word "Contiguous" is checked. This means that the computer will only select contiguous areas of color. If you want to select all areas of the same color across the entire image, uncheck this box. The picture (below, right) shows the result of using the Magic Wand with the Contiguous box unchecked. (In this picture, the tolerance has been raised to 100.)
You can select areas of the image using the Select menu. First, you can select the entire image by choosing "All." The keyboard shortcut is Ctrl + A. Once a selection has been made and you no longer need the selection area, you can choose "Deselect" to get rid of the selection. The shortcut for this is Ctrl + D. If you then want to select the exact same area again, you can choose "Reselect."The fourth item on the menu, "Inverse," is a handy function. It is often desirable to select a small area and then invert the selection so that everything except that area is selected. This can save you a great deal of time and can also be used to create interesting effects.
You can select areas of the image in a similar fashion to the Magic Wand tool by choosing the Color Range option. When you click on this menu item, the Color Range dialogue box will appear. Your cursor will change to look like an eyedropper. You can use this eyedropper to sample a pixel color from your image, and like the non-contiguous Magic Wand, similar colors across the entire image will be selected.
The benefit of using the Color Range dialogue box to make your selection is that you can see the area that will be selected in the black and white preview box. In the preview, the selected area is shown in white and the area not selected is shown in black. You can use your eyedropper to sample either from the original image or from the preview box, and you can keep making adjustments until you are satisfied with the selection area.
The "Fuzziness" scale above the preview box is like the tolerance factor for the Magic Wand. The higher the fuzziness, the more is selected.
To the right of the preview box are three eyedropper icons. The default allows only one color sampling at a time. If you click on the "+" eyedropper icon, any subsequent pixel colors that you sample will be added to the selection. If you click on the "-" eyedropper icon, any subsequent pixel colors that you sample will be subtracted from the selection. You can click on the "Invert" box to invert the selection area. When the selection is the way you want it, either hit the Enter key or click "OK."
After you have selected an area of the image, you can use the Select menu to alter the selection area. The "Feather" menu item acts the same as "Feather" in the Marquee menu, discussed earlier.
Clicking on "Modify" will bring up a sub-menu of options.
