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How can I write full gps coordinates in degrees, minutes, seconds format as a GPS exif tag to .tif images using python? I can write a portion of the gps coord using the piexif package (e.g. Longitude) if I only include the decimal and minutes as integers. However piexif throws a ValueError whenever I include seconds and fractions of a second. piexif will only accept a tuple containing two integers for the longitude, despite the standard calling for 3 integers.

Info on EXIF tags is available [here](http://www.cipa.jp/std/documents/e/DC- 008-2012_E.pdf)!

import piexif # pip install piexif from PIL import Image # PIL version 4.0.0 for compatability with conda/py3.6 fname = "foo.tiff" #read tiff file into a pillow image obj im = Image.open(fname) #readin any existing exif data to a dict exif_dict = piexif.load(fname) #GPS coord to write to GPS tag in dms format #long = 120° 37' 42.9996" East longitude LongRef = "E" Long_d = 120 Long_m = 37 Long_s = 42.9996 #add gps data to EXIF containing GPS dict #exif_dict['GPS'][piexif.GPSIFD.GPSLongitude] = (Long_d, Long_m) #this works exif_dict['GPS'][piexif.GPSIFD.GPSLongitude] = (Long_d, (Long_m,Long_s)) #this returns an error exif_dict['GPS'][piexif.GPSIFD.GPSLongitude] = (Long_d, Long_m, Long_s) #this also returns an error """ Traceback (most recent call last): File "<ipython-input-210-918cd4e2989f>", line 7, in <module> exif_bytes = piexif.dump(exif_dict) File "C:\Users\JF\AppData\Local\Continuum\anaconda3\lib\site-packages\piexif-1.0.13-py3.6.egg\piexif\_dump.py", line 74, in dump gps_set = _dict_to_bytes(gps_ifd, "GPS", zeroth_length + exif_length) File "C:\Users\JF\AppData\Local\Continuum\anaconda3\lib\site-packages\piexif-1.0.13-py3.6.egg\piexif\_dump.py", line 341, in _dict_to_bytes '{0} in {1} IFD. Got as {2}.'.format(key, ifd, type(ifd_dict[key])) ValueError: "dump" got wrong type of exif value. 4 in GPS IFD. Got as <class 'tuple'>. """ #convert updated GPS dict to exif_bytes exif_bytes = piexif.dump(exif_dict) #encode updated exif tag into image and save as a jpeg im.save(fname.replace('.tiff','.jpeg'), "jpeg", exif=exif_bytes)
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  • Did you try (Long_d, Long_m, Long_s)? Commented Aug 28, 2018 at 6:50
  • yes, it also throws the ValueError listed in the traceback commented out above. Commented Aug 28, 2018 at 18:17
  • Probably this will help. It is the reverse operation (getting GPS info from exif). Commented Aug 28, 2018 at 19:09

2 Answers 2

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Found this solution, There is great documentation here!!

http://www.cipa.jp/std/documents/e/DC-008-2012_E.pdf

https://piexif.readthedocs.io/en/latest/functions.html

Hope this is useful

import piexif #http://www.cipa.jp/std/documents/e/DC-008-2012_E.pdf #https://piexif.readthedocs.io/en/latest/functions.html exif_dict = piexif.load("test_exif.JPG") gps_ifd = {piexif.GPSIFD.GPSLatitudeRef:"N", piexif.GPSIFD.GPSLatitude:(2,2), piexif.GPSIFD.GPSLongitudeRef:"W", piexif.GPSIFD.GPSLongitude:(1,1), piexif.GPSIFD.GPSAltitudeRef:(0), piexif.GPSIFD.GPSAltitude:(1700,1) } exif_dict = {"0th":{}, "Exif":{}, "GPS":gps_ifd, "1st":{}, "thumbnail":None} exif_bytes = piexif.dump(exif_dict) piexif.insert(exif_bytes,"test_exif.JPG") exif_dict = piexif.load("test_exif.JPG") print(exif_dict)
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I haven't used piexif but according to their docs you need to specify the data in rational format as in (int, int):

exif_dict["GPS"][piexif.GPSIFD.GPSLongitude] = [(120, 1), (37,1), (429996, 10000)];

Basically use (numerator, denominator) to describe your values with integers.

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