Adobe 13102498 User Guide - Page 280

PHOTOSHOP CS3 273 User Guide Options available in the New Channel and Channel Options dialog boxes: Masked areas Sets masked areas to black (opaque) and selected areas to white (transparent). Painting with black increases the masked area; painting with white increases the selected area. When this option is selected, the Quick Mask button in the toolbox becomes a white circle on a gray background . Selected Areas Sets masked areas to white (transparent) and selected areas to black (opaque). Painting with white increases the masked area; painting with black increases the selected area. When this option is selected, the Quick Mask button in the toolbox becomes a gray circle on a white background Spot Color Converts an alpha channel to a spot color channel. Only available for existing channels. Color Sets the color and opacity of the mask. Click the color field to change the color. The color and opacity settings affect only the appearance of the mask and have no effect on how underlying areas are protected. Changing these settings may make the mask more easily visible against the colors in the image. Paint on a channel to mask image areas When the new channel appears at the bottom of the Channels palette, it is the only channel visible in the image window. Click the eye icon for the composite color channel (RGB, CMYK) to display the image with a color overlay showing the mask. ❖ Select the brush or an editing tool and do one of the following to add or subtract from the mask created from the alpha channel: • To remove areas in the new channel, paint with white. • To add areas in the new channel, paint with black. • To add or remove areas using opacities less than 100%, set the opacity in the options bar of the painting or editing tool and then paint with white or black. You can also paint with a color to achieve lower opacities. Save and load selections You can save any selection as a mask in a new or existing alpha channel and later reload the selection from the mask. You can use a selection as a layer mask by loading the selection to make it active, then adding a new layer mask. See also "Add layer masks" on page 319 Save a selection to a new channel 1 Select the area or areas of the image you want to isolate. 2 Click the Save Selection button at the bottom of the Channels palette. A new channel appears, named according to the sequence in which it was created. Save a selection to a new or existing channel 1 Use a selection tool to select the area or areas of the image you want to isolate. 2 Choose Select > Save Selection. 3 Specify the following in the Save Selection dialog box, and click OK: Document Chooses a destination image for the selection. By default, the selection is placed in a channel in your active image. You can choose to save the selection to a channel in another open image with the same pixel dimensions or to a new image.