Adobe Photoshop CS5 One-on-One

The petals are brightest in the Red channel, the stem is well-defined

in the Green channel, and the sky is lightest in the Blue channel

(see the colorized views in Figure 10-3).

High contrast, light petals and headUniform brightness, great detailGenerally dark with bright sky

Invert Blue, combine with RedInvert Blue, combine with Green5 minutes of hacking pieces together

Figure 10-3.

Figure 10-4.

Duplicating the Blue channel and inverting it makes the sky dark

and other portions of the image light, a step in the right direction.

Combining channels with Image→Calculations permits you to

emphasize portions of the image, such as the flower (see Figure 10-4,

left) or stem (middle). From there, it’s just a matter of selecting

the pieces you like, splicing them together, and adjusting contrast

values. After a few minutes of tinkering—a process that I explain

in detail later in this lesson—I arrived at the rough mask shown on

the right side of Figure 10-4. Five to ten minutes later, I completed

the mask and used it to select the flower.

340 Lesson 10: Creating and Applying Masks