Lesson 3 Review
Bitmap mode means the image consists of only pure black and pure white. A bitmap mode image is called a one-bit image and is also known as line art.Grayscale mode means that the image contains 256 levels of gray plus black and white. Grayscale mode is also called 8-bit.
RGB stands for red, green, and blue. This image mode is a full color image. Because it uses one 8-bit channel for each color -- red, green, and blue -- it is called a 24-bit color image (8 red + 8 green + 8 blue = 24).
Index mode allows you to limit the colors used in an image to specific palette. The indexed palette can have up to 256 unique colors.
The Web-safe alert is a small cube that appears when a color is selected that will shift or dither on systems that cannot display more than 256 colors.
Whenever the cursor appears as an eyedropper, you can click to change the foreground color.
While the color picker is open, you can click on an image inside Photoshop, to pick that color. Keep the mouse button down and move the cursor outside of Photoshop to pick colors from the desktop.
The keyboard shortcut for the eyedropper is I.
Holding Alt (Option on Mac) down when a painting tool is active temporarily changes to the eyedropper for selecting a new foreground color.
You can copy an image and place it into Photoshop Elements by going to File > New > Image from Clipboard.
Homework Assignment
Select an image or your own that has a pleasing range of colors. If necessary, crop the image to isolate the areas of color that are most pleasing. Convert the image to index mode. Save the Color Table (ACT) and then convert the color table to a custom swatch file (ACO) as described in the Custom Swatch Exercise. Post your swatch file in the forum to share with other students. An example image and swatch collection is shown here. (Click here to save the ACO Swatch Collection from my example.)