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January 2004
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2004.01.23 20:12 "Re: How to convert MINISBLACK to PHOTOMETRIC_RGB", by Chris Cox
At 1:55 PM -0500 1/23/04, Frank Warmerdam wrote: > Joris wrote: > > Frank Warmerdam wrote: > > > > > "sample" == "band" == "channel" == "component" == ? > > > > > > Thanks Frank. Now I know I finally did understand it correctly. Am I also > > correct in thinking that the only proper way ignorant software (as in > > software that doesn't know about how the image came about or what it is > > intended to contain) can correctly interpret this 3-channel image as a > > grayscale image with 2 extra channels that have no specified > > application/meaning? If ignorant software were to have to render this image, > > the correct thing to do is to render the first channel as grayscale, and > > discard the others as far as rendering is concerned, is that right? I > > realize this may also be trivial questions, but this thread is very > > confusing. > > Joris, > > I am by no means an authority on the TIFF specification. My interpretation > of the file in question is that a sensible application should render the > first band in greyscale and ignore the 2nd and 3rd since they are > extra samples > with no meaning attached. Or load the 2nd and 3rd channels as alpha (not transparency) channels -- as Photoshop does. It would be incorrect to interpret this image as RGB. Chris