Excluding Colors

Use Photoshop s Layer Style dialog box (see Figure 24.2) to exclude colors in the image. Advanced Blending excludes targeted information in a specific channel. With the exclusion sliders, you can omit colors of a specific brightness value.

Figure 24.2: The Advanced Blending controls in the Layer Style dialog box

To demonstrate how these sliders work, follow these steps:

1. Open the file Heavenly_Roses.psd from the ch24 folder on the CD (see Figure 24.3).

   
   Figure 24.3: The Heavenly Roses image

2. The image is divided into a layer and a Background. Double-click the Rose Layer icon, to display the Layer Style dialog box.

3. First, clear all of the Channels check boxes. The image of the roses disappears. Now check the red (R) box only. The channel information from the Red channel appears and affects the underlying layer. The Red channel appears to contain most of the detail of the red rose.

   Note  

   If you were to look at the information for the Rose layer in the Channels palette, you would see that the Red channel contains most of the detail of the red rose and more pixels with higher brightness values.

4. Check the green box and uncheck the red and blue boxes. Notice that there is more detail on the green rose when the green box is checked. The same is true for the blue rose.

5. Check all of the boxes to display the roses in full color .

You will now use the exclusion sliders to omit pixels of a specific brightness value within each channel:

1. Make sure Blend If is set to Gray.

2. Move the black This Layer slider to the right until the shadow value reads 90, as in Figure 24.4. The darker pixels in the roses disappear.

   
   Figure 24.4: Setting the channel options to Gray and the This Layer black exclusion slider to 90

3. Press Option (Mac) or Alt (Win) and click the Cancel button. It changes to the Reset button. In the Blend If list, choose Red. Move the black This Layer slider to the right until it reads 90. The dark pixels on the green and blue roses disappear, but almost all of the pixels on the red layer remain .

4. Press the Option/Alt key and click Reset. Now move the white slider to the left, until the highlight value reads 96. The red rose almost completely disappears.

If you use exclusion sliders to omit pixels of a specific brightness range from the layer, you force colors to disappear. This can produce harsh color transitions and jagged edges. You can diminish the effect by adjusting the Fuzziness setting, which softens the transition. Here s how: Press Option/Alt and click Reset. This time, press the Option/Alt key as you drag the left half of the white slider to the left. The effect on the red rose produces a softer edge, as in Figure 24.5.

Figure 24.5: You can achieve softer transitions by pressing the Option or Alt key while dragging half of a slider.