- Color Essentials
- Identifying a Color Cast
- Understanding Color Correction with Image Variations
- Mimicking the Color Darkroom with Color Balance
- Global Color Correction
- The Numbers Don't Lie
- Selective Color Correction
- Alleviating Extreme Color Problems
- Correcting Color Temperature Problems
- Interchannel Color Correction
- Closing Thoughts
Interchannel Color Correction
Photoshop offers many different perspectives for retouching. For example, my photographic training allows me to work out imaging solutions from a photographic and darkroom perspective, whereas people with a lot of prepress and printing experience will approach Photoshop from a different point of view. As I was working on this book, I had the pleasure of having my Photoshop eyes opened by Chris Tarantino, who comes to Photoshop with 20 years of dot-etching and high-end prepress experience.
When Chris looks at a CMYK file, the first thing he looks at is the flesh tones. As Chris explains, "When the flesh looks good, the viewer will be attracted to the product." His color correction process always starts by evaluating the individual color channels for tone, gradation, and transitions that he can take advantage of to shape the color of an image. Rather than working with Adjustment Layers, Chris does all his color correction through the Apply Image command. The Apply Image command allows you to mix varying amounts of different channels with each other with precise control.
In the following example, Chris color corrected the photograph of the model for a very demanding high-quality import catalog. As you can see in figure 4.108, the model's skin tones are too ruddy and, due to lack of tonal separation, the clothing is disappearing into the background. After applying interchannel color correction, the model's face is clear, and the sweater has been color corrected to match the merchandise, as shown in figure 4.109. Chris creates selection masks for each image element.
Figure 4.108 Before
Figure 4.109 After
Chris always starts with the skin tones, and upon inspecting the four channels (shown in figure 4.110), he saw that the magenta channel was too dark, blocked up, and lacking in detail. However, the cyan channel had a full range of gray throughout that he could use to add tone and detail to the magenta plate.
Figure 4.110 Chris starts by looking for detail, gradation, and information in each of the individual color channels.
Chris selected Image > Apply Image and, as shown in figure 4.111, he blended 25% of the cyan channel into the magenta channel. Interestingly enough, he used the magenta channel to mask itself out by checking Mask and Invert. Wherever the magenta channel had been dark, it would now be light, and the cyan grayscale information could be added to provide tonal detail for her face.
By using the better channel to replace the weaker one, Chris can simultaneously apply color correction and build up tonal and detail information, as you see in figure 4.112.
Figure 4.111 Chris uses the Apply Image command to add good cyan grayscale information to the weaker magenta plate.
Figure 4.112 After improving both the magenta and yellow color plates, the model's skin is much clearer.