[magick-developers] [PATCH] GPS and multivalued EXIF properties support

[Alexander E. Patrakov]

Hi,

the attached patch adds the functionality to extract GPS information 
from images. To do so, I also had to add support for multivalued EXIF 
properties (because, e.g., longitude is written as degrees, minutes and 
seconds, and we want to have all of that).

Also it changes the way how signed byte and unspecified properties are 
printed, to minimize loss of information.

Please review and, if possible, apply.

Testcase: 
http://akuaku.org/hiptop_images/default/2003-05-24_115510_28166_0.jpg

$ identify -format '%[exif:*]' 2003-05-24_115510_28166_0.jpg
exif:ColorSpace=1
exif:ComponentsConfiguration=1, 2, 3, 0
exif:DateTimeOriginal=2003:05:24 22:21:01
exif:ExifImageLength=176
exif:ExifImageWidth=144
exif:ExifOffset=180
exif:ExifVersion=48, 50, 50, 48
exif:FlashPixVersion=48, 49, 48, 48
exif:GPSAltitude=78/1
exif:GPSAltitudeRef=0
exif:GPSDateStamp=2003:05:24
exif:GPSInfo=290
exif:GPSLatitude=35/1, 36/1, 5767/100
exif:GPSLatitudeRef=N
exif:GPSLongitude=139/1, 41/1, 5034/100
exif:GPSLongitudeRef=E
exif:GPSMapDatum=WGS-84
exif:GPSProcessingMethod=65, 83, 67, 73, 73, 0, 0, 0, 72, 89, 66, 82, 
73, 68, 45, 70, 73, 88
exif:GPSTimeStamp=22/1, 29/1, 14/1
exif:GPSVersionID=2, 2, 0, 0
exif:ImageDescription=030524_2221~01
exif:Make=KDDI-TS
exif:Model=A5301T
exif:Orientation=1
exif:ResolutionUnit=2
exif:XResolution=72/1
exif:YCbCrPositioning=2
exif:YResolution=72/1

Yes, I don't like the result for GPSProcessingMethod, but it is still 
better than the 5-character string "ASCII".

-- 
Alexander E. Patrakov