Re: DRAFT: eXIf 2017-03-02

> On March 4, 2017 at 10:54 PM John Bowler <[email protected]> wrote:
> 
> 
> On Sat, Mar 4, 2017 at 3:01 PM, Glenn Randers-Pehrson <[email protected]> wrote:
> > Interesting.  Are you suggesting that an Exif profile containing only
> > a TIFF header plus (for example) an Orientation tag, a WaterDepth tag,  and a
> > GPSAltitude tag (without any IFD0, Exif IFD, or GPS IDF tags) would be valid?
> > It would be nice if that were so.
> 
> No; read the spec.
> 
> Personally I have no intention of doing that; there are two perfectly
> good libraries which I use both of which handle EXIF with minimal
> spec-reading on my part.  I do need to read the tag definitions, I do
> not need to understand the intricacies of how the data is stored on
> disk.

OK.  I don't want to remove the explanatory material about IFD0 and IFD1 but
I'll add the word "Therefore" to indicate that it's not a PNG specification
but an interpretation of the Exif specification.  I'll refer to the
Exif IFD and GPS IFD as "IFDs" rather than "sub-IFD's", to avoid inventing
new terminology.  And I'll add a requirement that any gap preceding an
IFD must be filled with buffer bytes of unspecified content.

Glenn

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