2 Questions about Histograms...
2 Questions about Histograms...
- Subject: 2 Questions about Histograms...
- From: "CS Carl Stawicki (4211)" <email@hidden>
- Date: Wed, 5 Sep 2001 11:05:32 -0400
Hey boys and girls-
Question #1:
I'm doing some testing of RGB files converted to different CMYK profiles and
setups, and would like to be able to count the tones I end up with per
channel. The way I'm doing it now is very tedious. I'm taking a screen shot
of each channel's histogram, opening in PS, zooming in, and manually
counting. The histogram itself inside the dialog is 256 pixels wide, one
pixel per (potential) tone, so I set my grid to 1 pixel to make it easier to
count. I count the empty spaces (missing tones) and subtract from 256 to get
my total number of tones the conversion left me with. This isn't fun,
people, trust me.
Is there a way to do this easier? The statistics in the histogram dialog are
not any help for determining the total number of tones, or are they?
NOTE TO ADOBE: Total number of tones would be a good statistic to include in
the histogram dialog!
Question #2:
Is there any mathematical relationship between the number of tones in the
luminosity channel and the ones in the individual channels (RGB or CMYK)?
For example:
One conversion I did was from Adobe RGB to a CMYK setup with 25% dot and
medium black. Starting with my test file with 256 RGB tones per channel, I
ended up with:
211 tones - luminosity
158 tones - cyan
129 tones - magenta
122 tones - yellow
161 tones - black
I know luminosity is the lightness of an image, but it is obviously not an
average of the four colors, so how exactly is it determined?
Thanks for everyone's help.
Carl