Do you think it might be useful to get in contact with the ISO committee?
For all practical purposes, the standard is "wrong" and should be updated.

I think this is the committee in question:
http://www.iso.org/iso/home/standards_development/list_of_iso_technical_committees/iso_technical_committee.htm?commid=45020

cheers,
-Mark

On Wed, Jun 1, 2016 at 7:02 PM, Larry Gritz <[email protected]> wrote:

> My guess is Photoshop was the first tool to consider this metadata and got
> it wrong, and everyone else is copying Photoshop.
>
>
> Yeah, that seems very likely to me.
>
> And here we are, about to take the only identified instance of software
> that got it right, and break it in order to be compatible with all the ones
> who got it wrong. :-(   (I see no practical alternative to this plan.)
>
>
> On Jun 1, 2016, at 1:34 PM, Jonathan Gibbs <[email protected]> wrote:
>
> This is just a totally fascinating study of modern software. It's
> fascinating that you have a spec as widely adopted as JFIF/JPEG, and
> clearly the original engineers did a good job specifying some important
> meta-data. I'm sure they had all sorts of use cases where this was
> important.
>
> And yet (a) very little software handles it at all, and (b) those who do
> get it wrong.
>
> When does Software Archeologist become a well-paid job? That would be an
> interesting thing to be called out of retirement to do some day. :)
>
> My guess is Photoshop was the first tool to consider this metadata and got
> it wrong, and everyone else is copying Photoshop.
>
> FWIW, Houdini's "mplay" image/flipbook viewer seems to ignore it too.
>
> --jono
>
>
> On Fri, May 20, 2016 at 1:36 AM Kevin Wheatley <[email protected]>
> wrote:
>
>> now I'm at work the best documentation I have is from ITU T.871 which
>> is ISO/IEC 10918-5:
>>
>> Units for the H (horizontal) and V (vertical) densities:
>> = X'00': units unspecified; H and V densities, expressed in dots per
>> arbitrary unit, specify only the pixel aspect ratio (width:height
>> pixel aspect ratio = Vdensity:Hdensity).
>>
>> which is more explicit than the JFIF 1.02 de facto standard, which was
>> what I read last night. JFIF 1.02 I thought could be read in an
>> ambiguous manner.
>>
>> This is much better, but reinforces something I mentioned to some
>> people yesterday; specifications should come with some form of
>> examples/reference implementation, especially when tying together
>> multiple standards or when there are variations supported due to
>> combining multiple proposals.
>>
>> Kevin
>> _______________________________________________
>> Oiio-dev mailing list
>> [email protected]
>> http://lists.openimageio.org/listinfo.cgi/oiio-dev-openimageio.org
>>
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>
> --
> Larry Gritz
> [email protected]
>
>
>
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>
>
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