Re: DRAFT: eXIf 2017-03-02

Glenn Randers-Pehrson <[email protected]> Fri, 3 Mar 2017 07:28:48 -0500
Newsgroups gmane.comp.graphics.png.general
Message-ID <CA+PdXcuxds=N_knHncd8RQuXeinHKuGG0bA=tAeBbRSuVcRZiw@mail.gmail.com>
On Fri, Mar 3, 2017 at 7:06 AM, John Bowler
<[email protected]> wrote:
> On Fri, Mar 3, 2017 at 3:39 AM, Glenn Randers-Pehrson <[email protected]> wrote:
>> On Fri, Mar 3, 2017 at 4:44 AM, Pavel Zlatovratskii <[email protected]> wrote:
>>> I think "and/or" should be read as "or IFD[0] or IFD[1] or both".
>>
>> Yes, that is what it means.
>
> That wasn't what I asked.   The *meaning* of the sentence is clear.  I
> don't understand why the data *has* to contain *either*.

OK.

I thought an empty eXIf chunk would be invalid, but looking again at
the Exif spec, it appears that an APP1 containing only a TIFF header
with both pointers 0 would be valid although useless.

So I suppose we should allow an empty eXIf chunk.

Glenn

------------------------------------------------------------------------------
Check out the vibrant tech community on one of the world's most
engaging tech sites, SlashDot.org! http://sdm.link/slashdot