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Message-ID: <077901c02e80$a30acee0$24a6d4d1@melange>
From: "Sam Leffler" <sam@errno.com>
To: "Frank Warmerdam" <warmerda@home.com>, "Rick LaMont" <lamont@lava.net>,
        "TIFF Mailing List" <tiff@olympiakos.com>
References: <m13gYv5-000odPC@malasada.lava.net> <39DC0598.8872025F@home.com>
Subject: Re: Varying BitsPerSample
Date: Wed, 4 Oct 2000 20:58:57 -0700
Organization: Errno Consulting
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> I would really like to see some of these (in particular the MINSAMPLEVALUE
> and MAXSAMPLEVALUE) handled on a per-sample in libtiff.  It would also
> be nice if the types of each sample could be controlled, though I think
this
> would result in datasets that work properly with very few packages.  It
> might be quite difficult to even get the libtiff tools programs to support
> this fully.
>
> In short, I am willing to work with you to make libtiff handle this
better,
> but I think it unwise to generate files like this if you actually want
them
> to work with any other software.
>
> I too would be interested in more educated opinions.
>

The documentation clearly states (or so I recall) that BitsPerSample must be
the same for each sample.  This was a conscious design decision based on my
experiences--that the vast majority of usage had each sample the same width
and that it wasn't worthwhile adding the complexity of varying bits per
sample.

You will find a couple other TIFF tags likewise constrained by the library.
All are/should be documented (I'm certain the manual pages state limitations
and the HTML documentation should as well).

    Sam


