Posted by
Kost on
Apr 14, 2021; 9:27am
URL: http://imagej.273.s1.nabble.com/Color-balance-The-operation-behind-tp5024606.html
Hi everybody,
Today I was trying to explain the color balance correction for a RGB images
and got stuck on understanding what operation ImageJ do when using the tool
Image > Adjust > Color balance in a specific channel.
I was reading the mathematics of color balance in Wikipedia but so far
without success.
https://en.wikipedia.org/wiki/Color_balance#Mathematics_of_color_balanceTo try to understand, I opened one image and then looked and one and only
pixel.
When not changing the color range in the red channel (original image), the
values in the channels were (168, 075, 095)
After selecting the minimum in the histogram for the channel red from 50 to
255 the values changed to (147, 075, 095) .
To wrap up:*
Original pixel value with R[0-255] = (168, 075, 095)
Edited pixel value with R[50-255] = (147, 075, 095)
How did ImageJ went from 168 to 147?
Thanks in advance for your help :)
Kind regards,
Kornelius
*Explanation of the notation:
The intensity in each channel are between parentheses (R,G,B) and the
selected range for a color channel is reported between square brackets; i.e.
original color range in the red channel = R[0-255]
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