tailieunhanh - Photoshop 6 for Windows Bible- P16

Photoshop 6 for Windows Bible- P16:If you are reading this foreword, it probably means that you’ve purchased a copy of Adobe Photoshop , and for that I and the rest of the Photoshop team at Adobe thank you. If you own a previous edition of the Photoshop Bible, you probably know what to expect. If not, then get ready for an interesting trip. | Chapter 9 Masks and Extractions 419 Tip When the mask is active you can likewise toggle the display of the image by press k ing the tilde key. Few folks know about this shortcut but it s a good one to 1 assign to memory. It works whether the Channels palette is open or not and it permits you to focus on the mask without moving your mouse all over the screen. Using a mask channel is different from using the quick mask mode in that you can edit either the image or the mask channel when viewing the two together. You can even edit two or more masks at once. To specify which channel you want to edit click the channel name in the palette. To edit two channels at once click one and Shift-click another. All active channel names appear highlighted. You can change the color and opacity of each mask independently of other mask channels and the quick mask mode. Double-click the mask channel name or choose the Channel Options command from the Channels palette menu. This command is dimmed when editing a standard color channel such as Red Green Blue Cyan Magenta Yellow or Black. A dialog box similar to the one shown back in Figure 9-11 appears but this one contains a Name option box so you can change the name of the mask channel. You can then edit the color overlay as described in the Changing the red coating section earlier in this chapter. Tip If you ever need to edit a selection outline inside the mask channel using paint and . . edit tools click the quick mask mode icon in the toolbox. It may sound a little like a play within a play but you can access the quick mask mode even when working within a mask channel. Make sure the mask channel color is different from the quick mask color so you can tell what s happening. Building a Mask from an Image So far everything I ve discussed in this chapter has been pretty straightforward. Now it s time to see how the professionals do things. This final section in this chapter explains every step required to create a mask for a complex .