GPS Data inconsistency with the Z1

Hi,

We know the Z1 does not have an inbuilt gps mechanism, it relies on the gps data from the phone and inserts that into the photo exif data. We have an ios app that sends the gps coordinates from the phone when the photo was clicked and are storing it in the database. When we compare the values from the database and the exif from the same image, there seems to be some difference. We thought as it is taking that data from the phone, the values would be exactly same, not even a 0.000000000001 difference, exactly the same. But the there seem to be differences such that just the first 3 or 4 digits after the decimal are the same, sometimes even values after the third digit are different. Is there any processing done with the gps data before it is inserted into the image exif? What is causing these differences? Is there any way that these values can be the same (without using a custom plugin for it)

Are you using the webAPI to save the metadata into the still image?

https://github.com/ricohapi/theta-api-specs/blob/main/theta-web-api-v2.1/options/gps_info.md

If so, post the snippet that you are using to store the information.

example:

{
    "gpsInfo": {
        "lat": 23.532,
        "lng": 23.532,
        "_altitude": 999.00,
        "_dateTimeZone": "2014:05:18 01:04:29+08:00",
        "_datum": "WGS84"
    }
}

Is the difference in the GPS coordinate due to the time taken to stitch and save the image inside the camera?

There is a discussion on the creation time and modification time.

EXIF Tag Documentation - #5 by craig

You may be able to get more information on the difference by opening an issue on GitHub on the API specification section.

https://github.com/ricohapi/theta-api-specs/tree/main/theta-web-api-v2.1

@sumeetgm89, I suggest that you talk to @Shotaro_Igami about this. If not here, then on Facebook.

Are you referring to these discussions?

Not specifically @craig, it is just that over the years I have become to know @Shotaro_Igami as very knowledgeable when it comes to using the Z1 for mapping and the issues with getting it correct.

1 Like

@JoscTr this is great insight. I hope that @sumeetgm89 is able to get in touch with him.

Thanks for your help. :slight_smile:

Thank you @craig and @JoscTr for your responses.
@craig , we are not doing anything explicitly to feed the gps data into the image, it just comes along with the picture. It is not about accuracy, what i meant is that if it is getting the data from the phone then the data should be exactly identical, what we get from the ios app and what is extracted from the image, both should be the same if the time is the same.

@JoscTr I will try to get in touch with @Shotaro_Igami , thank you very much for your guidance

Are you using the official RICOH mobile app for iOS? Or, did you build your own app?

If you wrote your own app, are you saying that the values you are storing from lat and lng are not reflected in the image metadata?

https://github.com/ricohapi/theta-api-specs/blob/main/theta-web-api-v2.1/options/gps_info.md

Are you saying that when you store a floating point number into the image metadata that the number stored is not the same as the number you attempted to save?

{
    "gpsInfo": {
        "lat": 23.532,
        "lng": 23.532,
        "_altitude": 999.00,
        "_dateTimeZone": "2014:05:18 01:04:29+08:00",
        "_datum": "WGS84"
    }
}

If you store this number -122.0087393 using the API, does the number change when you read it from the metadata?