Adobe 23101335 User Guide - Page 196

186 CHAPTER 7 Using Channels and Masks Viewing channels You can use the palette to view any combination of individual channels. For example, you can view an alpha channel and the composite channel together to see how changes made in the alpha channel relate to the entire image. By default, individual channels are displayed in grayscale. To display the Channels palette: 1 Choose Windows > Show Channels, or click the Channels palette tab. 2 Use the scroll bars or resize the palette to see additional channels. When a channel is visible in the image, an eye icon ( ) appears to its left in the palette. To show or hide a channel: Click in the eye column next to the channel to show or hide that channel. (Click the composite channel to view all default color channels. The composite channel is displayed whenever all the color channels are visible.) To show or hide multiple channels, drag through the eye column in the Channels palette. These guidelines apply to channels you display: • In RGB, CMYK, or Lab images, you can view the individual channels in color. (In Lab images, only the a and b channels appear in color.) • If more than one channel is active, the channels always appear in color. • In alpha channels, selected pixels appear as white; unselected pixels appear as black (partially transparent or selected pixels appear as gray). These are the channel default options. • If you display an alpha channel at the same time as color channels, the alpha channel appears as a transparent color overlay, analogous to a printer's rubylith or a sheet of acetate. To change the color of this overlay or set other alpha channel options, see "Creating alpha channels (Photoshop)" on page 200. Changing the display of the palette You can show the individual color channels in color (rather than grayscale) in the Channels palette and specify the size of the thumbnails. Using thumbnails is the most convenient way of tracking channel contents; however, turning off the display of thumbnails can improve performance. To show color channels in color: 1 Choose Edit > Preferences > Display & Cursors. 2 Select Color Channels in Color, and click OK. To resize or hide channel thumbnails: 1 Choose Palette Options from the Channels palette menu. 2 Select a display option: • Click a thumbnail size. Smaller thumbnails reduce the space required by the palette-helpful when you're working on smaller monitors. • Click None to turn off the display of thumbnails. 3 Click OK.