Steps Applied

To help in practicing extractions, I have provided a tutorial image and scenario where it is useful to apply basic color correction. The image used in making the tutorial is available so that you can experiment with the process and results. Please download that image here: Color Correction Image.

The Scenario

The example image was taken on an overcast day which tints the entire scene blue. While the result is not awful, they can be greatly and quickly improved with a levels correction. The correction will both balance the color and improve contrast. A final correction with Color Balance can add richness to the corrected color. There is no magic here, just quick, solid technique which can yield greatly improved image results in just a few moments.

The Steps

1. Open the image (a.jpg).

2. Open the Levels function (Cmd-L)[CTRL+L]. See Figure 1.

3. Switch to the Red channel by using either the popup menu or key commands (Cmd-1)[CTRL+1].

4. Using the sliders, crop the histogram. See Figure 2.

5. Repeat step 5 for the Green (Cmd-2)[CTRL+2] and Blue (Cmd-3)[CTRL+3] channels. See Figure 3 and Figure 4.

6. Return to the composite RGB Levels, and observe the effect of the changes by looking at the image and make midtone adjustments accordingly. See Figure 5.

7. Close the Levels by clicking the [ok] button. Accepting the changes will redistribute RGB color information. The result will increase contrast and will tend to balance image color.

[NOTE: your monitor must be calibrated for the following steps.]

8. Open Color Balance (Cmd-B)[CTRL+B].

9. Swing the top slider (Cyan Red) to the right and left of center while watching the image. If the change to either side creates something visually pleasing, swing the slider through the full range on that side (-100 to 0, or 0 to +100), and decide the best position based on what you see on screen.

10. Repeat Step 9 for the middle (Magenta Green) and bottom (Yellow Blue) sliders.

11. Repeat Step 8 and 9 to help rebalance the color. Because each slider is adjusted separately, adjusting again can better optimize how the sliders affect one another. These second changes may be minimal.

12. Click the Highlight button (in the Tone Balance panel) and repeat Steps 9 thru 11.

13. Click the Shadow button (in the Tone Balance panel) and repeat Steps 9 thru 11.

14. Close the Color Balance by clicking the [ok] button. This will apply the changes.

15. Compare the before and after changes for the original state (Open), the Levels correction (Levels) and Color Balance adjustment (Color Balance) by clicking on the appropriate states on the History palette.

 

  Copyright © Richard Lynch 2001