This was moved from anothter thread after complaints.
I use Corel PhotoPaint, so the process I use is a bit different. I found a link to instructions for doing it in PhotoShop here:
Understanding Channels
In PhotoPaint, I go to Image > Split Channels > RGB.
This breaks up the 24-bit RGB image into 3 separate 8-bit images representing the red, green and blue channels in the image.
So, say that I wanted to turn this image into a nice black and white:
I could just convert directly to greyscale, which would give me this:
It's not bad actually, but we can do better.
I split the image into its three RGB component channels:
Red
Green
Blue
As you can see, the representative colours in each channel are lighter, and the absence of those colours is darker. The green is by far my favourite (most contrast without details such as the sunflower being totally black) and I might end up going with just the green.
If I'm not satisfied, I can always play with assembling the three images back into an RGB image, but putting them back in a different order. In this case, I put the green into the red, the blue into the green and the red into the blue. You can always play with the best combo. Sure looks weird...
...but then convert back to an 8-bit greyscale and you get a more contrasty image (though subtly so) than the simple conversion.
Of course, then I'm always tempted to crank the gamma down to 0.7 and ruin everything...but sometimes I like the results:
As I said, try other combinations (like leaving the green in its own channel but swapping the red and blue). Every image is different. It's fun to play with and see what you can get.
Hope that helps...
James.
Message edited by author 2003-08-17 12:14:27. |
