Google Photos Metadata

[dgood]

Like many of you, I use Google Photos. But I never knew how they managed metadata. So after getting inspiration from Carl Seibert's post: https://www.carlseibert.com/xmp-iptciim-or-exif-which-is-preferred/, I thought I'd conduct my own experiment.

I put in a unique date, time and caption for EXIF, XMP and IPTC to see from which fields Google Photos would pull. I put Exif with a 2018 year and a caption that said "This is the EXIF field." XMP was 2017 and IPTC was 2016.

Based on my experiment, Google Photos pulls the Description (caption) from XMP and the Date/Time stamp from EXIF. Weird.

Code Select Expand


---- ExifTool ----
ExifTool Version Number         : 10.71
---- System ----
File Name                       : 2017-07-15 15.04.29.jpg
Directory                       : /Users/devingoodman/Desktop
File Size                       : 1854 kB
File Modification Date/Time     : 2018:03:08 22:44:48-08:00
File Access Date/Time           : 2018:03:08 22:49:04-08:00
File Inode Change Date/Time     : 2018:03:08 22:44:48-08:00
File Permissions                : rw-r--r--
---- File ----
File Type                       : JPEG
File Type Extension             : jpg
MIME Type                       : image/jpeg
Exif Byte Order                 : Big-endian (Motorola, MM)
Current IPTC Digest             : 7fb68bd8b59779487813391236ab2f91
Image Width                     : 2656
Image Height                    : 1772
Encoding Process                : Baseline DCT, Huffman coding
Bits Per Sample                 : 8
Color Components                : 3
Y Cb Cr Sub Sampling            : YCbCr4:4:4 (1 1)
---- IFD0 ----
Image Description               : This is the EXIF field 2018-01-01
X Resolution                    : 72
Y Resolution                    : 72
Resolution Unit                 : inches
Y Cb Cr Positioning             : Centered
---- ExifIFD ----
Exif Version                    : 0231
Date/Time Original              : 2018:01:01 20:18:00
Components Configuration        : Y, Cb, Cr, -
Flashpix Version                : 0100
Color Space                     : Uncalibrated
---- GPS ----
GPS Version ID                  : 2.3.0.0
---- IPTC ----
Application Record Version      : 4
Date Created                    : 2016:01:01
Time Created                    : 20:16:00-08:00
Caption-Abstract                : This is the IPTC field 2016-01-01
---- XMP-x ----
XMP Toolkit                     : Image::ExifTool 10.71
---- XMP-dc ----
Description                     : This is the XMP field 2017-01-01
---- Adobe ----
DCT Encode Version              : 100
APP14 Flags 0                   : [14], Encoded with Blend=1 downsampling
APP14 Flags 1                   : (none)
Color Transform                 : YCbCr
---- Composite ----
Date/Time Created               : 2016:01:01 20:16:00-08:00
GPS Latitude                    : 42 deg 22' 19.76" N
GPS Latitude Ref                : North
GPS Longitude                   : 71 deg 0' 53.97" W
GPS Longitude Ref               : West
GPS Position                    : 42 deg 22' 19.76" N, 71 deg 0' 53.97" W
Image Size                      : 2656x1772
Megapixels                      : 4.7
Good-MacBook:~ Good$


Also, I tried putting in two different locations simultaneously for GPS under EXIF and XMP, but I wasn't able to do it. I put in the XMP GPS first and then a different EXIF GPS. I was never able to get the EXIF GPS coordinates to take.
I've attached the JPEG here so you guys can test on whatever cloud system you use.
Hope this is helpful to someone.

[dgood]

If you're relying on Google to manage your pictures, I'd advise against it. It's a great photo viewing cloud service with a compelling AI component, but it isn't a DAM, so don't use it like that.

I uploaded a photo with all metadata erased.
exiftool -all= file.jpg
Then uploaded that photo to Google Photos. I put in a caption and changed the date via their web interface and subsequently downloaded the updated picture. There seems to be no caption or date on this picture at all, which leads me to believe Google isn't updating the file metadata at all.

Code Select Expand


---- ExifTool ----
ExifTool Version Number         : 10.71
---- System ----
File Name                       : bird (1).jpg
File Size                       : 1850 kB
File Modification Date/Time     : 2018:03:09 09:11:57-08:00
File Access Date/Time           : 2018:03:09 09:12:03-08:00
File Inode Change Date/Time     : 2018:03:09 09:12:01-08:00
File Permissions                : rw-r--r--
---- File ----
File Type                       : JPEG
File Type Extension             : jpg
MIME Type                       : image/jpeg
Image Width                     : 2656
Image Height                    : 1772
Encoding Process                : Baseline DCT, Huffman coding
Bits Per Sample                 : 8
Color Components                : 3
Y Cb Cr Sub Sampling            : YCbCr4:4:4 (1 1)
---- Adobe ----
DCT Encode Version              : 100
APP14 Flags 0                   : [14], Encoded with Blend=1 downsampling
APP14 Flags 1                   : (none)
Color Transform                 : YCbCr
---- Composite ----
Image Size                      : 2656x1772
Megapixels                      : 4.7


[carlseibert]

Thanks for reading my blog!

I don't think I've ever looked at Google Photos treatment of metadata (despite the fact that my phone backs up to there). But I did look at Drive a while ago, and IIRC, got about the same results: some meager attempt at displaying the caption and no ability to edit at all. That could be pretty darned frustrating for somebody didn't know and put in a bunch of time trying to mark up assets.

As far as reading from the XMP, rather than the more expected IIM is concerned, sometimes that might be from strict compliance with the MWG Guidelines, which include some fairly strange logic. But I kind of doubt it in this case. (There's a link from the Glossary post on my blog. Just search "glossary in the search box. The interesting part starts on about page 22.)

The good news is that, at least in Drive, when you download a photo, wherever was there to start with is preserved.

Flickr sort of works the same way, up to a point, by the way. It reads the caption, but edits made in Flickr aren't written to the file. Then, frustratingly, only the "Original" size download includes metadata. So people who are generous enough to share their work may be rewarded by having stripped, copyright information and caption-less copies floating all over the internet. And now that I think about it, the same problem exists for Creative Commoners at Wikimedia Commons. Metadata is only preserved on the largest size download!

[StarGeek]

One thing you can do if you spent time updating metadata on Google Photos is use Google Takeout.  Google Takeout will give you a Json file which you can use to update to file with exiftool.  I documented how to do it in this StackOverflow question.  The exact command does change over time, because...  well, Google is Google.