Posted by
Karsten Rodenacker on
Feb 14, 2007; 10:41am
URL: http://imagej.273.s1.nabble.com/Grayscale-values-for-RGB-images-tp3700260p3700269.html
... OK it is not surprising to get the same results since 8-bit and
Measure applies the same weighting rule for RGB to grey. However it
should be clear what is really measured. Possibly a weighting
(0.,1.,0.), only green channel, would reflect slightly better what
should be measured!?
KR
Am 14.02.2007 um 11:31 schrieb Karsten Rodenacker:
> Be careful, your 'green' image can be a green RGB image or an 8-bit
> image with green look-up-table.
> Measure will apply for RGB images a default weighting which can be
> changed by setRGBWeights() macro function. See e.g. Edit->Options-
> >Conversions.
> Quite surprising that you get the same results. Typically RGB
> Conversion is weighted, e.g. by red*.3+green*.59+blue*.11! or any
> other values!
>
> Regards
> KR
>
> Am 13.02.2007 um 22:24 schrieb Jacqui Ross:
>
>> I think I must have missed an update somewhere. Usually, if I want to
>> measure intensity of RGB images, I have to change them to grayscale
>> first (8bit) but it seems that I don't need to include this extra
>> step
>> now. I seem to get the same results whether I change my green
>> image to
>> grey or not. Is this correct?
>
> Karsten Rodenacker
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Karsten Rodenacker
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GSF - Institute of Biomathematics and Biometry
D-85758 Oberschleissheim Postfach 11 29
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