Hi, on another thread, FMW has helped with a script that converts an image to grayscale and appends the mean value of gray to the filename, but when i compare this mean value with one in photoshop's histogram tab, they do not match.
I've been using this page as reference: http://kb2.adobe.com/cps/315/315207.html that mentions how to convert levels to % and backwards. I'm plugging the number from photoshop but nothing is matching. Any input please?
Level = 256 - [(256)(P)/100]
IM %: 11.2288
Calculated level: 227.254272
Percentage = .390625(256 - L)
photoshop mean: 28.64
Calculated %: 88.8125
Photoshop histogram mean value != IM mean value
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fmw42
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Re: Photoshop histogram mean value != IM mean value
That paper seems to be about INK densities and not graylevels.
To convert from 8-bit graylevel (range 0 to 255), say call it V (for any R,G,B channel or grayscale) to percent, you simply do:
100*V/255=value in percent
To convert from 8-bit graylevel (range 0 to 255), say call it V (for any R,G,B channel or grayscale) to percent, you simply do:
100*V/255=value in percent