Hello:
I am working with the GPS latitude longitude tags.
In my application, the format I use is a bit different form what it comes
from the Exif, so I have to modify it.
Since I do not have samples of ALL West-East North-South Coordinates,
after doing the changes I am not sure if that will work for all the
4 corners of the world plus the fact that degrees can be 1,2 or 3 numbers
and the same can happen with minutes and seconds.
So :
a) The exif format for the coordenates is equal ALL OVER?
b) Where could I get the exact format that for this coordinates (explaining the 1,2,3 number position)
c) Is there a way to get some image samples with this coordenates
or as another possibility only valid EXIFs
d) the tag GPS Longitude/latitude comes with two different possibilities
GPS Longitude : 135 deg 46' 29.56"
GPS Longitude : 135 deg 46' 29.56" E
with and without The W-E
Is there a way to avoid it.
e) I could try to use a image and put the test coordenates into it...
IF
I do that... regardless of the format I introduce (a valid format)
will the result placed on the exif will be unique? and equal to .. for example
a coordenate taken with a camera, or it could be several similar format.
....
I hope muy questions are clear... sorry for the cuantity ;)
Emilio
Hi Emilio,
The EXIF GPSLatitude and GPSLongitude tags do not contain N/S or E/W information, but the XMP ones do. For EXIF you must also write GPSLatitudeRef and GPSLongitudeRef. Use -G1 -a to extract all values and see where they came from. ExifTool also creates a Composite value from the related EXIF tags to make things easier for copying to XMP.
Internally, EXIF stores coordinates as 3 rational values. ExifTool handles this for you and allows you to use many different formats. Use the -v option when reading to see exactly what was written.
- Phil
From Exif Spec:
GPS expressed as three RATIONAL values giving the degrees, minutes, and
seconds, respectively. If latitude is expressed as degrees, minutes and seconds, a typical format would be
dd/1,mm/1,ss/1. When degrees and minutes are used and, for example, fractions of minutes are given up to two
decimal places, the format would be dd/1,mmmm/100,0/1.
To get E/W and S/N information you need to refer GPSLongitudeRef and GPSLatitudeRef respectively.
(Not that I am answering your question, just adding to Phil's answer)
Hi Phil:
Thanks ... that makes my work simpler and more understandable.
Emilio
Quote from: Phil Harvey on October 14, 2010, 02:06:51 PM
Hi Emilio,
The EXIF GPSLatitude and GPSLongitude tags do not contain N/S or E/W information, but the XMP ones do. For EXIF you must also write GPSLatitudeRef and GPSLongitudeRef. Use -G1 -a to extract all values and see where they came from. ExifTool also creates a Composite value from the related EXIF tags to make things easier for copying to XMP.
Internally, EXIF stores coordinates as 3 rational values. ExifTool handles this for you and allows you to use many different formats. Use the -v option when reading to see exactly what was written.
- Phil
mvadu:
Thanks... for the clarifications.... there are so many options
that it was difficult to see the correct way.
With this it is more easy.
Emilio
Quote from: mvadu on October 14, 2010, 09:23:01 PM
From Exif Spec:
GPS expressed as three RATIONAL values giving the degrees, minutes, and
seconds, respectively. If latitude is expressed as degrees, minutes and seconds, a typical format would be
dd/1,mm/1,ss/1. When degrees and minutes are used and, for example, fractions of minutes are given up to two
decimal places, the format would be dd/1,mmmm/100,0/1.
To get E/W and S/N information you need to refer GPSLongitudeRef and GPSLatitudeRef respectively.
(Not that I am answering your question, just adding to Phil's answer)
Just to reiterate my point: It doesn't matter how you write the coordinates. ExifTool will reformat them appropriately and convert them to the 3 rational values stored in the EXIF.
- Phil