Exif.GPSInfo.{GPSLongitude,Latitude} are not decoded

[dr who]

the GPS latitude and longitude data is not decoded: use the example picture at http://d2h.net/gallery/d/20568-4/DSCF1390.JPG

exiv2 -Pkyctv /downloads/DSCF1390.JPG | grep GPS
Exif.Image.GPSTag Long 1 1313 1313
Exif.GPSInfo.GPSVersionID Byte 4 2 0 0 0 2 0 0 0
Exif.GPSInfo.GPSLatitudeRef Ascii 2 N North
Exif.GPSInfo.GPSLatitude Rational 3 47/1 3817443/1000000 0/1 47deg 3.81744'
Exif.GPSInfo.GPSLongitudeRef Ascii 2 E East
Exif.GPSInfo.GPSLongitude Rational 3 8/1 41359940/1000000 0/1 8deg 41.35994'
Exif.GPSInfo.GPSAltitudeRef Byte 1 0 Above sea level
Exif.GPSInfo.GPSAltitude Rational 1 1908629/1250 1526.9 m
Exif.GPSInfo.GPSMapDatum Ascii 7 WGS-84 WGS-84

pyexiv2 however returns:

import pyexiv2
image = pyexiv2.Image('/downloads/DSCF1390.JPG')
image.readMetadata()
print image['Exif.GPSInfo.GPSLongitude']
(8L, 1L)
print image['Exif.GPSInfo.GPSLatitude']
(47L, 1L)

the value for altitude is correct, though:

print image['Exif.GPSInfo.GPSAltitude']
(1908629L, 1250L)

which comes out as:
1908629/float(1250)
1526.9032

[Olivier Tilloy (osomon)]

Successfully reproduced with the given example file.
Unfortunately, multiple value fields for EXIF tags are currently not correctly dealt with: only the first value is extracted and returned.

[Olivier Tilloy (osomon)]

In fact this bug conflicts with the fix provided for bug #146323. pyexiv2 should always return all the values held in a given field even if it is not supposed to hold more than one value.

[Olivier Tilloy (osomon)]

Fix committed with revision 79.
Multiple value fields for EXIF tags are now fully decoded and returned as a tuple of values.
Here is an example script and its output for the attached image:

image = pyexiv2.Image('DSCF1390.JPG')
image.readMetadata()
for key in image.exifKeys():
    if key.find('GPS') != -1:
        print key, ':', image[key], ':', image.interpretedExifValue(key)

Exif.Image.GPSTag : 1313 : 1313
Exif.GPSInfo.GPSVersionID : 2 0 0 0 : 2 0 0 0
Exif.GPSInfo.GPSLatitudeRef : N : North
Exif.GPSInfo.GPSLatitude : ((47L, 1L), (3817443L, 1000000L), (0L, 1L)) : 47deg 3.81744'
Exif.GPSInfo.GPSLongitudeRef : E : East
Exif.GPSInfo.GPSLongitude : ((8L, 1L), (41359940L, 1000000L), (0L, 1L)) : 8deg 41.35994'
Exif.GPSInfo.GPSAltitudeRef : 0 : Above sea level
Exif.GPSInfo.GPSAltitude : (1908629L, 1250L) : 1526.9 m
Exif.GPSInfo.GPSMapDatum : WGS-84 : WGS-84

This fix reverts the behaviour implemented with revision 70 to fix bug #146323.

[dr who (dr-who)]

excellent! works as advertized :-) thx!

[Ian Barton (ian-manor-farm)]

There still seems to be a problem with this in revision 103:

>>> image = pyexiv2.Image('29052008409.jpg')
>>> image.readMetadata()
>>> for key in image.exifKeys():
... if key.find('GPS') != -1:
... print key, ':', image[key], ':', image.interpretedExifValue(key)
...
Exif.Image.GPSTag :
Traceback (most recent call last):
  File "<stdin>", line 3, in <module>
  File "/usr/lib/python2.5/site-packages/pyexiv2.py", line 594, in __getitem__
    value = self.__getExifTagValue(key)
  File "/usr/lib/python2.5/site-packages/pyexiv2.py", line 467, in __getExifTagValue
    tagType, tagValue = self.__getExifTag(key)
ValueError: too many values to unpack

Ian.

[Ian Barton (ian-manor-farm)]

Sorry forgot to add that you can download the image I used from: http://www.ian-barton.com/ian-barton/wiki/uploads/Ireland/29052008409.jpg

Ian.

[dmoore (damien-moore)]

Attached is the patch i'm using for this issue in phraymd (I use a local copy of the pyexiv2.py source inside phraymd)

[Olivier Tilloy (osomon)]

Fixed in the 0.2 branch. The expected syntax for the original example would now look like this:

    import pyexiv2
    metadata = pyexiv2.ImageMetadata('/downloads/DSCF1390.JPG')
    metadata.read()
    for key in ('Exif.GPSInfo.GPSLongitude',
                'Exif.GPSInfo.GPSLatitude',
                'Exif.GPSInfo.GPSAltitude'):
        tag = metadata[key]
        print key, ':', tag, '|', tag.human_value

The expected output is:

Exif.GPSInfo.GPSLongitude : 8/1, 41359940/1000000, 0/1 | 8deg 41.35994'
Exif.GPSInfo.GPSLatitude : 47/1, 3817443/1000000, 0/1 | 47deg 3.81744'
Exif.GPSInfo.GPSAltitude : 1908629/1250 | 1526.9 m