When I speak of neutralizing images, I mean that I want to make the image true to its natural color. For instance, I want my blacks to be a black, not yellowish black or bluish black, but black black. I want my white areas to be white, not a pink tone or off-white. Neutralizing an image is an attempt to do this.
In RGB, it's pretty easy to obtain a neutral look in a full color image. Usually, if you balance the highlight and shadow areas, the rest of the image will fall into place. For instance, if you started with the image Figure 3-37, look for the whitest area in the image and make of the values in the image the same.
Figure 3-37. The original shot needs neutralization
For example, make a white area R5, G5, B5. You can use the Curve adjustment tool or the Selective color correction tool to set the highlight and shadow area neutral points, as shown Figure 3-38. Use the Color Sampler tool and the Information palette to see what the values are as you make changes with the color correction tools to balance these two areas.
Figure 3-38. Adjust the highlight with the Curve adjustment tool to a perfectly even number in all channels
You don't want to blow out an area to the point that there are no values left there. You may get rid of any subtle shape ...