Image Magick's Explanation of Gamma: "Gamma level of gamma correction. The same color image displayed on two different workstations may look different due to differences in the display monitor. Use gamma correction to adjust for this color difference. Reasonable values extend from 0.8 to 2.3. You can apply separate gamma values to the red, green, and blue channels of the image with a gamma value list delineated with slashes (e.g. 1.7/2.3/1.2)."

Gamma has several uses. The first one, is one I call "Gamma Fade". What this does is what it sounds like. It fades an image.

Have you ever been on a page where the background and text blended together? I have. I had to highlight the text to read what was on the page. Frustrating and unnecessary. They should have faded the background or used a different one.

Besides fading, you can also bring color back into a faded image. And another use for fading or bringing the color back, is Imagery. You can use it when creating your wonderful works of art.

Below are example of these uses. I will not show the images because the page would load too slow if I did. But of course, I will have links to the images.

Hummingbirds This is the original image I will use.

Use parameter below 1, such as .99 to .01, to either bring the color back into a faded image, or darken the color in another. Here are some examples:

• gamma at .40
  
• gamma at .20

  Black and white old photos can be brought back to life.

  • Original B & W
    
  • Gamma .40

  Now to fade images.

  • gamma at 2
    
  • gamma at 10

  Finally, an imagery example:

  • Creating distance
    
  • The steps I took

  ---

  "Gamma RGBs--Filtering color"

  Have you ever had a picture that had too much of one color? It was too red? Too blue? Too green? Or maybe not enough of one of them? Well, the Gamma RGBs can fix that. Yep, you can filter the color you don't want and keep the ones you do. Or filter in more of the color you want. Sometimes it's best to keep a little of the colors you want out for better results.

  This is the Image I will use.

  Before, I used number parameters like .30 or 2. Now, we will be using parameters involving the RGB (RED--GREEN--BLUE). They appear like this with a comma separating the colors: 1.5,2.1,1.9 or with a / (1.5/2.1/1.9). I recommend using the commas because you can get different results when using slashes. Commas are more reliable, and you get what you want or what you think you want. Here are some examples: Commas VS Slashes

  • Commas01,1.6,2.6
    
  • Slashes .01/1.6/2.6

  • Only red 2.9,.0,.0 filtering out all but red.
    
  • Majority blue .90,.30,1.9

  All but blue looked bad. Therefore, I added a little of the other two colors to improve it..

  Try both commas and slashes to see the results. You might like one better then the other, or they may be the same.

  Now continuing on....the 1.5 represents Red. The 2.1 represents Green. The 1.9 represents Blue. The higher the number, the more of that color is filtered in or the lower the number that much is filtered out. Below are examples:

  • RED 2.9,2.5,1.5
    
  • GREEN 1.7,2.9,2.2
    
  • BLUE 1.3,1.7,2.9

  You can bring about different colors by continuing the filtering process after each time, and keep going until you get what you want. Play around with it.

  
  

  ---

  
  

  RGB and GRAY SHADE (Embossed)

  
  I took the same tree image and embossed it using gray shade 100.

  Trees embossed

  I will add a color wash to the image using the same RGB parameters as above. I spiffed the embossed image 3 times to bring out the highlights more before adding color.

  • RED embossed Parameters 2.9,2.5,1,5
    
  • GREEN embossed Parameters 1.7,2.9,2,2
    
  • BLUE embossed Parameters 1.3,1.7,2.9
    
  • ALL three.

  After doing the blue wash, I went back and added first the red, and then the green parameters. Like I mentioned above, you can bring out different colors by keep using the RGBs and using different parameters each time without reversing your work. Explore and discover the wonders of Gamma for yourself.

  
  

  ---

  
  

  "Gamma and Negatives"

  
  It's time to now play around with the more extreme use of Gamma. The Negative. It's best to use the negatives from -1 to -20. The higher the negative number the darker the image. The lower negatives has an unusual effect you will have to see and try.

  • Gamma -10 Hummingbirds
    
  • Gamma -5 Hummingbirds
    
  • Gamma -1 Hummingbird
    
  • Gamma -2 Trees

  Have fun and create some really wild images........

  
  
  Susanna