Adobe® Photoshop® CS2 Studio Techniques

Using Color Channels

If you leave the pop-up menu at the top of the Blending slider area set to gray, then Photoshop will ignore the colors in your document and just analyze the brightness of the image (as if the image were in Grayscale mode). By changing this menu, you will be telling Photoshop to look at the information in the individual color channels to determine which areas should be visible (Figure 15.24). For example, if you have a document that is in CMYK mode and you change the pop-up menu to cyan and move the upper-right slider to 26, you'll make all areas of the layer that contain 10% or less cyan disappear. This can be useful when you want to remove a background that contains one dominant color.

Figure 15.24. The Blend If pop-up ...