adding EXIF datetime to Narrative Clip jpegs

[chuckkahn]

Where does Google+ pick up it's "UTC -4" timezone cues in my iPhone photos?

http://i.imgur.com/5BzJ0du.jpg

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ExifTool Version Number         : 9.59
File Name                       : IMG_7810.JPG
Directory                       : /Users/chuckkahn/Pictures/Camera - iPhone 5S
File Size                       : 3.3 MB
File Modification Date/Time     : 2014:07:04 20:18:04-04:00
File Access Date/Time           : 2014:07:20 16:24:40-04:00
File Inode Change Date/Time     : 2014:07:20 16:22:50-04:00
File Permissions                : rw-------
File Type                       : JPEG
MIME Type                       : image/jpeg
Exif Byte Order                 : Big-endian (Motorola, MM)
Make                            : Apple
Camera Model Name               : iPhone 5s
Orientation                     : Horizontal (normal)
X Resolution                    : 72
Y Resolution                    : 72
Resolution Unit                 : inches
Software                        : 7.1.2
Modify Date                     : 2014:07:04 20:18:04
Y Cb Cr Positioning             : Centered
Exposure Time                   : 1/570
F Number                        : 2.2
Exposure Program                : Program AE
ISO                             : 32
Exif Version                    : 0221
Date/Time Original              : 2014:07:04 20:18:04
Create Date                     : 2014:07:04 20:18:04
Components Configuration        : Y, Cb, Cr, -
Shutter Speed Value             : 1/570
Aperture Value                  : 2.2
Brightness Value                : 7.792568203
Metering Mode                   : Multi-segment
Flash                           : No Flash
Focal Length                    : 4.1 mm
Run Time Flags                  : Valid
Run Time Value                  : 177015423136250
Run Time Scale                  : 1000000000
Run Time Epoch                  : 0
HDR Image Type                  : Unknown (2)
Sub Sec Time Original           : 054
Sub Sec Time Digitized          : 054
Flashpix Version                : 0100
Color Space                     : sRGB
Exif Image Width                : 3264
Exif Image Height               : 2448
Sensing Method                  : One-chip color area
Scene Type                      : Directly photographed
Custom Rendered                 : Unknown (2)
Exposure Mode                   : Auto
White Balance                   : Auto
Focal Length In 35mm Format     : 30 mm
Scene Capture Type              : Standard
Lens Info                       : 4.12mm f/2.2
Lens Make                       : Apple
Lens Model                      : iPhone 5s back camera 4.12mm f/2.2
GPS Latitude Ref                : North
GPS Longitude Ref               : West
GPS Altitude Ref                : Above Sea Level
GPS Time Stamp                  : 00:18:03.38
GPS Img Direction Ref           : True North
GPS Img Direction               : 336.231441
Compression                     : JPEG (old-style)
Thumbnail Offset                : 1830
Thumbnail Length                : 10832
Image Width                     : 3264
Image Height                    : 2448
Encoding Process                : Baseline DCT, Huffman coding
Bits Per Sample                 : 8
Color Components                : 3
Y Cb Cr Sub Sampling            : YCbCr4:2:0 (2 2)
Aperture                        : 2.2
GPS Altitude                    : 113.9 m Above Sea Level
GPS Latitude                    : 43 deg 40' 9.70" N
GPS Longitude                   : 79 deg 21' 11.15" W
GPS Position                    : 43 deg 40' 9.70" N, 79 deg 21' 11.15" W
Image Size                      : 3264x2448
Run Time Since Power Up         : 2 days 1:10:15
Scale Factor To 35 mm Equivalent: 7.3
Shutter Speed                   : 1/570
Create Date                     : 2014:07:04 20:18:04.054
Date/Time Original              : 2014:07:04 20:18:04.054
Thumbnail Image                 : (Binary data 10832 bytes, use -b option to extract)
Circle Of Confusion             : 0.004 mm
Field Of View                   : 61.9 deg
Focal Length                    : 4.1 mm (35 mm equivalent: 30.0 mm)
Hyperfocal Distance             : 1.87 m
Light Value                     : 13.1


Because Google+ doesn't read any "UTC -4" from my "exiftool'd" Narrative Clip photos.

http://i.imgur.com/SPeA6mn.jpg

Code Select Expand

ExifTool Version Number         : 9.59
File Name                       : 005655.jpg
Directory                       : /Users/chuckkahn/Pictures/Narrative Clip/2014r/07/20
File Size                       : 804 kB
File Modification Date/Time     : 2014:07:20 10:55:46-04:00
File Access Date/Time           : 2014:07:20 16:30:01-04:00
File Inode Change Date/Time     : 2014:07:20 16:29:41-04:00
File Permissions                : rw-r--r--
File Type                       : JPEG
MIME Type                       : image/jpeg
JFIF Version                    : 1.01
Exif Byte Order                 : Big-endian (Motorola, MM)
Camera Model Name               : Narrative Clip
Orientation                     : Rotate 270 CW
X Resolution                    : 0
Y Resolution                    : 0
Resolution Unit                 : inches
Modify Date                     : 2014:07:19 20:56:55
Y Cb Cr Positioning             : Centered
Exif Version                    : 0230
Date/Time Original              : 2014:07:19 20:56:55
Create Date                     : 2014:07:19 20:56:55
Components Configuration        : Y, Cb, Cr, -
Flashpix Version                : 0100
Color Space                     : Uncalibrated
Image Width                     : 2592
Image Height                    : 1944
Encoding Process                : Baseline DCT, Huffman coding
Bits Per Sample                 : 8
Color Components                : 3
Y Cb Cr Sub Sampling            : YCbCr4:2:2 (2 1)
Image Size                      : 2592x1944


P.S.: added .csv of the two jpegs.

[Hayo Baan]

Perhaps for the GPS location?

[Phil Harvey]

The only way to store time zone in standard EXIF is to write GPSTimeStamp (which is UTC) and some other EXIF date/time tag (which is in the local time zone).  Although, if your time zone is 12 hours from UTC, you would also have to write GPSDateStamp to be able to differentiate +12:00 from -12:00.

- Phil

[Hayo Baan]

The only way to store time zone in standard EXIF is to write GPSTimeStamp (which is UTC) and some other EXIF date/time tag (which is in the local time zone).  Although, if your time zone is 12 hours from UTC, you would also have to write GPSDateStamp to be able to differentiate +12:00 from -12:00.

Hi Phil, nope, it much "simpler" than that. Apparently Google uses the gps location to determine the correct timezone. The image that shows the -4 offset had gps location info, the other didn't. Checking the location reveals that it was a shot taken in Toronto which indeed has the -4 hours timezone offset

Cheers,
Hayo

[Phil Harvey]

Hi Hayo,

I wasn't making a statement about how Google determines the time zone, they may well do it your way.  However, this is an indirect method to determine the time zone.  In my opinion it is simpler to just subtract GPSTimeStamp from DateTimeOriginal, rather than to look up the GPS position on a time zone map (and account for regional daylight savings times too).

- Phil

[Hayo Baan]

I wasn't making a statement about how Google determines the time zone, they may well do it your way.  However, this is an indirect method to determine the time zone.  In my opinion it is simpler to just subtract GPSTimeStamp from DateTimeOriginal, rather than to look up the GPS position on a time zone map (and account for regional daylight savings times too).

Ha, I think I initially misunderstood your comment
Now I read it correctly, I actually think Google may be doing it that way (as it is more direct and a bit simpler). But either way, the point I was trying to make to chuckkahn was that it's because of the GPS info, Google knows what the timzezone is. As there is no GPS information available in the second sample image, google can't determine the timezone.

[chuckkahn]

The only way to store time zone in standard EXIF is to write GPSTimeStamp (which is UTC) and some other EXIF date/time tag (which is in the local time zone).  Although, if your time zone is 12 hours from UTC, you would also have to write GPSDateStamp to be able to differentiate +12:00 from -12:00.

- Phil

I can't find any GPSDateStamp in the iPhone EXIF, so maybe GPSTimeStamp will do for Google+?   Also I can't find anything on the exiftool man page about how to write GPSTimeStamp (which would be the same UTC time I pull from the filename using -alldates before I shift it by 4 hours).   So is there an -alldatesandgpstimestamptoo command?

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exiftool '-alldates<\${directory}\$filename' -execute -alldates-=4 -model='Narrative Clip' -common_args -r -overwrite_original -progress /Users/chuckkahn/Pictures/Narrative\ Clip/2014

P.S.: I just tried re-uploading the same Narrative Clip photo to Google+ and the "UTC-4" came through.  The only difference was I used the desktop web page uploader this time.  Last time I used the Auto Backup for desktop Mac app.

Soon as I saw the Auto Backup for desktop Mac app uploads appearing without the "UTC-4" on them, I suspended the app.   Now I've restarted the app to see if it still does the same.

[Phil Harvey]

So is there an -alldatesandgpstimestamptoo command?

Unfortunately GPSTimeStamp is necessarily a bit more strict about the date/time formatting (so it can recognize if there is a date, and skip over it if there is), so you can't set GPSTimeStamp from FileName as you are for AllDates.  But you can set it from any of the AllDates tags afterwards, in the same command as your AllDates shift.  AllDates is a shortcut for DateTimeOriginal, CreateDate and ModifyDate.  So you could do this:

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exiftool '-alldates<\${directory}\$filename' -execute -alldates-=4 '-gpstimestamp<createdate' -model='Narrative Clip' -common_args -r -overwrite_original -progress /Users/chuckkahn/Pictures/Narrative\ Clip/2014

- Phil

[chuckkahn]

So is there an -alldatesandgpstimestamptoo command?

Unfortunately GPSTimeStamp is necessarily a bit more strict about the date/time formatting (so it can recognize if there is a date, and skip over it if there is), so you can't set GPSTimeStamp from FileName as you are for AllDates.  But you can set it from any of the AllDates tags afterwards, in the same command as your AllDates shift.  AllDates is a shortcut for DateTimeOriginal, CreateDate and ModifyDate.  So you could do this:

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exiftool '-alldates<\${directory}\$filename' -execute -alldates-=4 '-gpstimestamp<createdate' -model='Narrative Clip' -common_args -r -overwrite_original -progress /Users/chuckkahn/Pictures/Narrative\ Clip/2014

- Phil

That works great.  Now I think Google+ Auto Backup for Desktop is mangling the UTC info because uploading that way gives a timestamp with "UTC" but uploading via the web gives the correct "UTC-4" timestamp.   

[chuckkahn]

Looks like Google+ Auto Backup for Desktop will pull "UTC-4" from iPhone photos, as this example image uploaded that way shows in the right panel:

http://i.imgur.com/CMowP1U.jpeg

Or check out Google+ post with same minute photos from both cameras:

https://plus.google.com/u/0/103861167345611812134/posts/D4cYMiq17Hv?pid=6040907276026416578&oid=103861167345611812134

So where is Google+ looking and how can I satisfy that in my Narrative Clip photos if gpstimestamp won't?

[Phil Harvey]

You can do this investigation yourself by selectively deleting metadata from the iPhone photo until Google+ no longer knows the time zone.

- Phil

[chuckkahn]

You can do this investigation yourself by selectively deleting metadata from the iPhone photo until Google+ no longer knows the time zone.

- Phil

This does it:

Code Select Expand

exiftool -gpslongitude= -gpslatitude=

And to be precise, Google+ no longer knows it if it is uploaded using the Google+ Auto Backup for Desktop app.   Photos uploaded via the web to Google+ preserve the timezone.

https://plus.google.com/u/0/+ChuckKahn/posts/5DvkS9jxVsD