Posted by
Harry Parker on
Jan 03, 2008; 4:28pm
URL: http://imagej.273.s1.nabble.com/Superimpose-tp3697641p3697647.html
Dear Jinglei,
What you observe sounds normal to me. Your eyes/brain are much more sensitive to color hue shifts than light intensity variation. So you would probably not notice that the light intensity is slightly less, but you would notice small differences in the ratio of the colors.
--
Harry Parker
Senior Systems Engineer
Digital Imaging Systems, Inc.
----- Original Message ----
From: Jinglei Yang <
[hidden email]>
To:
[hidden email]
Sent: Wednesday, January 2, 2008 5:46:14 PM
Subject: RGB analysis
Dear All,
I have a question about how to analyze the color change of a small
sphere.
The sphere is compressed with increasing load. The projective image
sequences are recorded using a color imaging system. Its color will
change
and expand from gray to purple/blue starting from the center of the
bead
with increasing load.
I use Plugins->Macros->RGB histogram to analyze the RGB change. Both
the
entire area of the sphere and a constant centralized area are
considered.
But the byte values of RGB all decreased with increasing load! The
values of
Red and Green decreased more obviously than that of Blue.
However, I thought the value of blue should increase because I can
watch the
color changing to purple/blue by naked eyes.
I have no background of chromatics. Does anyone here give any
suggestions
about this issue?
Thank you very much!
Happy New Year!
Jinglei Yang
@UIUC
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