[Closed] Geolocation Question

The right place to speak and share about your experiences of GraphicConverter
Buadhai
Posts: 19
Joined: Mon Jan 02, 2017 3:04 am

[Closed] Geolocation Question

Post by Buadhai » Thu Jun 15, 2017 8:11 am

I recently downloaded the iOS DSLR Camera app. If I view photos taken with this app in the iOS Photos app, the Photos app shows the correct location in which the photo was taken. Likewise, the Koredoko iOS app shows the correct location as well as the correct GPS coordinates.

However, if I open these photos with GC 10.4.2, the geolocation data is not there. All the "Show Position…" menu items are greyed out and the Information window shows no GPS data.

My question is: Where is this geolocation data stored such that both Photos and Koredoko can "see" it, but GC cannot?

Koredoko screenshot showing correct location and GPS coordinates:
2017-06-15 12.59.33.png
2017-06-15 12.59.33.png (465.4 KiB) Viewed 914 times

EXIF data copied from GC. No GPS data appears:
screenshot 2017-06-15 at 13.09.44.jpg
screenshot 2017-06-15 at 13.09.44.jpg (104.54 KiB) Viewed 914 times

User avatar
forum_adm
Site Admin
Posts: 363
Joined: Fri Dec 23, 2016 9:41 am
Location: Germany
Country: Germany
Contact:

Re: Geolocation Question

Post by forum_adm » Fri Jun 16, 2017 6:32 pm

Please e-mail the image file zipped to lemke@lemkesoft.de
The screenshot is useless to find the bug.

Buadhai
Posts: 19
Joined: Mon Jan 02, 2017 3:04 am

Re: Geolocation Question

Post by Buadhai » Fri Jun 16, 2017 11:52 pm

I don't think it's a bug in GC, I think it's a bug or other weirdness in the way iOS handles GPS data. Clearly, the GPS data is there (somewhere) while the photo is on the iPhone. But, it's not in the EXIF data; it's somewhere else. An EXIF viewer can't see it, but the Photos app and the Koredoko app can.

As soon as I copy the photo to a Mac (or iPad), the GPS data is gone. GC can't see it. Preview can't see it.

I will email the photo, but I don't think that's going to answer the question.

User avatar
forum_adm
Site Admin
Posts: 363
Joined: Fri Dec 23, 2016 9:41 am
Location: Germany
Country: Germany
Contact:

Re: Geolocation Question

Post by forum_adm » Sat Jun 17, 2017 10:48 am

I checked your image.
It contains no GPS data. Even Photos do not see it.

What did you do exactly?
Screen Shot 2017-06-17 at 08.37.56.jpg
Screen Shot 2017-06-17 at 08.37.56.jpg (190.67 KiB) Viewed 893 times
Screen Shot 2017-06-17 at 08.37.34.jpg
Screen Shot 2017-06-17 at 08.37.34.jpg (151.29 KiB) Viewed 893 times

Buadhai
Posts: 19
Joined: Mon Jan 02, 2017 3:04 am

Re: Geolocation Question

Post by Buadhai » Sat Jun 17, 2017 11:34 am

Here's the issue. While the photo, taken with the DSLR camera app, is still on the iPhone, the Photos app and the Koredoko app can see the GPS data. For proof, see the attached screenshots:

IMG_6552.JPG
IMG_6552.JPG (204.07 KiB) Viewed 892 times
IMG_6553.JPG
IMG_6553.JPG (203.72 KiB) Viewed 892 times
But, the GPS data is not part of the EXIF, it is stored somewhere else:

IMG_6554.JPG
IMG_6554.JPG (131.16 KiB) Viewed 892 times

User avatar
forum_adm
Site Admin
Posts: 363
Joined: Fri Dec 23, 2016 9:41 am
Location: Germany
Country: Germany
Contact:

Re: Geolocation Question

Post by forum_adm » Sun Jun 18, 2017 9:52 am

So, that app do not store the data correctly inside the images.

Buadhai
Posts: 19
Joined: Mon Jan 02, 2017 3:04 am

Re: Geolocation Question

Post by Buadhai » Sun Jun 18, 2017 3:13 pm

I don't know where it stores the GPS data. What I do know is that the Apple Photos app knows how to read it and that the iOS app Koredoko, knows how to read it. But, it doesn't appear in any EXIF reader application.

Here's a screenshot of the Photos app displaying the correct location, even though the GPS data fields in the EXIF data are empty.
2017-06-17_08.29.44.jpg
2017-06-17_08.29.44.jpg (75.74 KiB) Viewed 881 times
Here's a screenshot of the Koredoko iOS app displaying the correct location along with the correct GPS coordinates.
koredoko.jpg
koredoko.jpg (63.78 KiB) Viewed 881 times
Here's a screenshot of the EXIFviewer app. No GPS data.
ExifViewer.jpg
ExifViewer.jpg (43.08 KiB) Viewed 881 times

User avatar
forum_adm
Site Admin
Posts: 363
Joined: Fri Dec 23, 2016 9:41 am
Location: Germany
Country: Germany
Contact:

Re: Geolocation Question

Post by forum_adm » Mon Jun 19, 2017 7:41 am

So, you should ask the developer of that app.
GPS data has to be stored normally inside EXIF and/or XMP data section to be visible for other apps.
Or is there maybe an XMP sidecar file which you did not copy from the iPhone.

Buadhai
Posts: 19
Joined: Mon Jan 02, 2017 3:04 am

Re: Geolocation Question

Post by Buadhai » Mon Jun 19, 2017 2:28 pm

So, you think the developer of this app created a special method of storing GPS data and then persuaded Apple to modify their iOS Photos app to be able to use this special method?

This seems highly unlikely to me.

After a week, still no response from the developer.

Buadhai
Posts: 19
Joined: Mon Jan 02, 2017 3:04 am

Re: Geolocation Question

Post by Buadhai » Wed Jun 21, 2017 12:52 am

Mystery Solved:

I asked the author of Koredoko, the iOS photo mapping app, about getting a photo’s location even if there is no GPS data in the EXIF header.

Here’s his answer:

"iOS Photo library may hold location information even if there is no information in Exif-GPS. Koredoko looks for location information in the order of Photo library, Exif-GPS.”

Post Reply