Support JFIF metadata

[GoogleCodeExporter]

I received an email from "Y.B." with a patch that adds JFIF support:

The patch mainly adds ability to parse JFIF data (APP0) - I needed it for the 
resolution info. EXIF (APP1) does not provide reliable one, at least for my set 
of images.
I also makes it possible to read all SOFx (not only SOF0) i.e. SOF2 - 
"Progressive, Huffman" JPEG encoding.
Some of the date/time fields are returned as java.util.Date and the user can 
use them formatted.

I would be happy if you find my patch useful and include it (entire or part) in 
the next version.

Original issue reported on code.google.com by drewnoakes on 25 Apr 2011 at 10:04

Attachments:

• jfif.patch

[GoogleCodeExporter]

Patch has been merged in revision 29 
(http://code.google.com/p/metadata-extractor/source/detail?r=29).

JFIF support was included.

Code for reading of SOFx segments was included but is commented out until 
further testing can be performed.

Code for parsing dates at the time they are read was also included but 
commented out.  Parsing dates applies the timezone of the computer doing the 
parsing, which may be different to the timezone in which the camera was 
operating.  Returning a Date object might be misleading.  Unfortunately the 
date string in the Exif segment doesn't include a timezone.  This idea is open 
for discussion, but the most reliable solution is to let people parse datetimes 
from strings, if they need to.

Original comment by drewnoakes on 25 Apr 2011 at 12:10

• Changed state: Fixed