On Jun 17, 5:03=A0am, rajani_sp <rajani...@[EMAIL PROTECTED]
> wrote:
> On Jun 17, 12:54=A0pm, Martin Leese <ple...@[EMAIL PROTECTED]
>
> wrote:
>
>
>
>
>
> > Arutperumjothi wrote:
> > > On Jun 17, 10:34 am, Martin Leese
<ple...@[EMAIL PROTECTED]
>
> > > wrote:
> > >> Arutperumjothi wrote:
> > >>> Hi all,
> > >>> I am new to image processing . i have two images taken with
differen=
t
> > >>> white balance adjustments.
> > >>> i need to compare this and say which one has more white balance .
Ca=
n
> > >>> anybody tell me how can I do this. =A0I am trying out this with
Matr=
ox
> > >>> image processing library and AForge.Net.
> > >> Don't understand. =A0I understand what white
> > >> balance is. =A0I don't understand what you
> > >> mean by "more white balance". =A0I don't see
> > >> how white balance can be something you can
> > >> have more of.
> > > Sorry for not being clear in query.
> > > I have taken two images with web cam by =A0white balance adjustments
(=
I
> > > guess i should be saying correcting white balance ) . I need to
> > > compare the two images. Please tell me how can i compare these two
> > > images.
>
> > Compare for what purpose? =A0What is your
> > goal? =A0Why do you want to do this?
>
> > Also, stuffing the two images on a website
> > somewhere and posting the link is always
> > helpful.
>
> > There are many ways to compare two images.
> > For example, you can just look at them.
>
> > --
> > Regards,
> > Martin Leese
> > E-mail: ple...@[EMAIL PROTECTED]
> > Web:http://members.tripod.com/martin_leese/-Hide
quoted text -
>
> > - Show quoted text -
>
> Hi,
>
> Thank you for the response. =A0I have uploaded the images in the below
>
link.http://groups.google.com/group/aforge/web/WB-Levels-BeforeAfter.jpeg
> I have to compare the images and output the result as =A0which of the
> images
> has the =A0correct white balance. In the pictures in the above link we
> can see the
> second image looks more natural. =A0 Ofcourse manually we can see both
> images
> and say which of them is better. Similarly i compare the luminosity of
> the two images
> and say which one is brighter picture. =A0Hope this is clear.
>
> Thanks
> Rajani- Hide quoted text -
>
> - Show quoted text -
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Rajani:
Why don't you just convert both images to CIELAB color space (just use
the "book" formula if you don't have a way to calibrate the images,
such as a Macbeth chart), and then calculate a "Delta E" image.
(Without calibration, you'll just get arbitrary, uncalibrated numbers
but still useful for comparison.) You might want to constrain your
analysis to the "white" area, such as the wall. Then you could look
at a histogram of the Delta E image or even boil it down into a single
"average Delta E" for the whole region. Delta E is the color
difference (look it up). It takes into account differences in
Lightness, Chroma (Saturation), and Hue, all boiled down into one
simple, easy to digest number. Of course you could also look at the
individual delta L, delta C, delta H if you want more detail. You
also might try asking in sci.engr.color.
Regards,
ImageAnalyst
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