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MahaB82A
December 1, 2022
Answered

Color information

  • December 1, 2022
  • 3 replies
  • 2526 views

If you select RGB, Info panel shows what are the colors are there. For example if you select AFTER EFFECTS Info panel shows: 

R:147

G:26

B:26

A:225

 

Color information

 

What is the purpose of having separate R, G, B?

 

 

 

 

This topic has been closed for replies.
Correct answer Rick Gerard

What is meant by "There is no color in the color channels".?


All channels are values from darkest to lightest. In 8-Bit color, there are 256 possible shades of gray for each channel. The values are displayed with numbers from 0 to 255. Change to 16-Bit color, and you now have the maximum possible number from 0 to 32,768 per channel. Change to 32-Bit color and the count now changes from 0 to 1, but it is calculated using floating-point, which means that there are 16777216 different values available because of the number of decimal places available, so that's an almost unlimited number of distinct values for each color channel. 

 

Colors are produced when you calculate the difference between the available color channels. If you look only at the value of a single color channel, there is no color. If you look at the red channel and ignore the other channels, the channel can only get brighter or darker. Black or White. 

 

You could artificially supply zero values to the Green and Blue channels and create a red display on your screen, but if you only look at one value, you only get something bright or dark. You have to calculate the difference between all three channels if you are going to get color. Otherwise, all you are going to see is black and white. It is often useful to look at the different values as an image, but unless you artificially add in a Zero value for the missing colors, you just get a black-and-white image.

Did you follow all that?

 

 

 

3 replies

thepixelsmith
Community Expert
Community Expert
December 1, 2022

Are you asking why you have the ability in After Effects to view the  invidual color channels in the Comp panel?

MahaB82A
MahaB82AAuthor
December 1, 2022

Yes, you are absolutely correct.

thepixelsmith
Community Expert
Community Expert
December 1, 2022

It's a preview tool just like being able to see the alpha information in the comp window.

Sometimes there may be an abberation that only appears in one of the color channels so being able to isolate and preview them individually may help with troubleshooting. 

When color grading or correcting it can be helpful to isolate the preview to get a better idea of the color breakdown of your composite video.
The same function is available in most video and graphics programs, they just call it different things, like how Photoshop calls it the Channels panel.

Mylenium
Legend
December 1, 2022

You have to go back to how computer graphics started out as CRT tubes and there were three differently colored dots for each pixels that would be stimulated with an electron beam. That's where all this comes from.

 

Mylenium

MahaB82A
MahaB82AAuthor
December 1, 2022

That means RGB is evolved from R, G, B. So that R, G, B is not much useful currently. 

Mylenium
Legend
December 1, 2022
MahaB82A
MahaB82AAuthor
December 1, 2022

What is the purpose of having separate R, G, B?