↓ Discovering exiftool
So something that I discovered a little bit ago was that I didn’t think about removing EXIF data from images, and so I manually used the view info dialogue in Windows to remove the private data from the photos.
In making A Day on the Trails, I wanted to make sure that I wasn’t including any of that info, so I looked for a more UNIX approach and found exiftool.
To install on macOS: brew install exiftool :P
It’s found a lot more data than I expected:
day-on-the-trails % exiftool ips-044B4F7A-A39D-457B-8611-6EC795937010.mp4
ExifTool Version Number : 11.70
File Name : ips-044B4F7A-A39D-457B-8611-6EC795937010.mp4
Directory : .
File Size : 6.3 MB
File Modification Date/Time : 2019:12:31 20:21:06-06:00
File Access Date/Time : 2019:12:31 20:21:06-06:00
File Inode Change Date/Time : 2019:12:31 20:29:37-06:00
File Permissions : rw-r--r--
File Type : MP4
File Type Extension : mp4
MIME Type : video/mp4
Major Brand : MP4 v2 [ISO 14496-14]
Minor Version : 0.0.1
Compatible Brands : isom, mp41, mp42
Movie Data Size : 6552485
Movie Data Offset : 44
Movie Header Version : 0
Create Date : 2020:01:01 02:21:04
Modify Date : 2020:01:01 02:21:06
Time Scale : 44100
Duration : 9.97 s
Preferred Rate : 1
Preferred Volume : 100.00%
Preview Time : 0 s
Preview Duration : 0 s
Poster Time : 0 s
Selection Time : 0 s
Selection Duration : 0 s
Current Time : 0 s
Next Track ID : 3
Track Header Version : 0
Track Create Date : 2020:01:01 02:21:04
Track Modify Date : 2020:01:01 02:21:06
Track ID : 1
Track Duration : 9.97 s
Track Layer : 0
Track Volume : 100.00%
Balance : 0
Audio Format : mp4a
Audio Channels : 2
Audio Bits Per Sample : 16
Audio Sample Rate : 44100
Matrix Structure : 1 0 0 0 1 0 0 0 1
Image Width : 720
Image Height : 1280
Media Header Version : 0
Media Create Date : 2020:01:01 02:21:04
Media Modify Date : 2020:01:01 02:21:06
Media Time Scale : 600
Media Duration : 10.01 s
Media Language Code : und
Handler Type : Video Track
Handler Description : Core Media Video
Graphics Mode : srcCopy
Op Color : 0 0 0
Compressor ID : avc1
Source Image Width : 720
Source Image Height : 1280
X Resolution : 72
Y Resolution : 72
Bit Depth : 24
Video Frame Rate : 29.98
Date/Time Original : 2019:12:27 13:41:47-06:00
Image Size : 720x1280
Megapixels : 0.922
Avg Bitrate : 5.26 Mbps
Rotation : 0
The really nice part is that you can then drill down into the details you want by using grep.
day-on-the-trails % exiftool content/day-on-the-trails/IMG_4040.jpeg | grep -i exposure
Exposure Time : 1/275
Exposure Program : Program AE
Exposure Compensation : 0
Exposure Mode : Auto
The -i asks grep to be insensitive to case, so that ‘Exposure’ and ‘exposure’ and ‘ExPoSuRe’ will all match!
Update:
To delete all GPS data via exiftool run exiftool -gps:all= a.jpg.