Effective Gray Scale Techniques By: Wilfredo C. Ileto Many people believe that color images will always be more effective than grayscale. I don’t agree with that perception. Grayscale can be just as visually powerful as color images when they are properly rendered. As a matter of fact, many of the great masterpieces in photographic history, such as those by Ansel Adams and Cartier Bresson, are grayscale images. While the trend has been moving towards full color reproduction, printing of grayscale or monotone images will always remain part of the printing process. Therefore, it is of great importance that we understand the process of converting color to grayscale and acquire the techniques to ...view middle of the document...
In the sample described above, the elements of the color image were composed of colors with the same luminosity. Converting the image to gray scale resulted in elements with similar tonal value. Thus the image simply disappeared. Another problem is that the dominant primary color will always have the most effect on the grayscale values in any particular area. If this dominant color lacks detail and contrast, the result will be a grayscale image which is likewise flat and
lacking in detail. This is most noticeable in the images of people, particularly Asians with yellow dominant in their flesh tones. The problem with the yellow in flesh tones is that it is strong in value and but lacking in detail. Merely converting a color image to grayscale using “Change Mode” in Photoshop can produce flesh tones that are dark and flat.
Change Mode to Grayscale
In order to address the problems discussed, it is clear that we need to control the strength that each of the colors contributes to the tonal values in the grayscale image. Using the RGB Channels for Grayscale Conversion The quickest method for effectively producing a grayscale image is to simply view the RGB image in its different color channels and select the channel which shows the best grayscale image. Please note that we should work with the file in its RGB mode because in a CMYK image some of the tonal values in the CMY channels have been transferred to the black channel. This is especially noticeable in images with strong black values in the shadow and near shadow areas. The procedure is as follows: 1. Apply auto level if needed. 2. Open the Channel Palette to preview of the grayscale image in each of the RGB channels. 3. Select the channel with the best grayscale image. 4. Convert from RGB to grayscale using the Change Mode command.
Conversion from Red Channel
Using the Channel Mixer for Grayscale Conversion A longer but more precise procedure involves the use of the Channel Mixer tool of Photoshop.(illustration 10) The Channel Mixer allows us to apply different levels of strength from each of the color channels. We can mix the amount that each channel contributes to the tonal value of the grayscale image to achieve the desired effect.
1. Apply auto level if needed. 2. Open the Channel Palette to preview of the grayscale image in each of the RGB channels. 3. Determine the channel with the best grayscale image. 4. Open the channel mixer. 5....