https://bugzilla.wikimedia.org/show_bug.cgi?id=13172
--- Comment #18 from Lupo <[email protected]> 2010-01-25 10:47:23 UTC --- re: exif_read_data returning a single rational: Yes, I also understand the EXIF spec to say that GPS coordinates are always three rationals. It appears, however, that actual implementations apparently treat it as "at most three rationals". Note that the current implementation works for files that have the coordinates as single fractional degrees. An example file is http://commons.wikimedia.org/wiki/File:DubocePark.jpg The file linked contains in the GPS IFD the sequence 00 02 00 05 00 00 00 01 00 00 0E DF which is "00 02"->(tag: GPSLatitude), "00 05"->(type: Rational), "00 00 00 01"->(count: 1), "00 00 0E DF"->(offset for value > 4 bytes). The value at the offset is then "02 40 51 8C 00 0F 42 40", which is 37769612/1000000, i.e. 37.769612 degrees. So it appears that either the Nikon D80 used for that image generates incorrect EXIF, or our understanding of the standard is wrong. The interpretation of "up to three" appears to be consistent with the TIFF 6.0 standard http://partners.adobe.com/public/developer/en/tiff/TIFF6.pdf to which the EXIF standard explicitly defers to in its section 4.6.2. In either case it appears that our code should be able to handle up to three rational values, not just exactly three values. It looks as if exif_read_data does this, returning a single rational for File:DubocePark.jpg, which has only one value in the EXIF, but returning an array if there are several values in the EXIF. Other EXIF viewers also can cope with "up to three" rationals; they don't require exactly three. -- Configure bugmail: https://bugzilla.wikimedia.org/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are the assignee for the bug. You are watching all bug changes. _______________________________________________ Wikibugs-l mailing list [email protected] https://lists.wikimedia.org/mailman/listinfo/wikibugs-l
