Sorting Photo by EXIF

It has been seven months since my last post.

Preface

Goal: Automate file renaming using BASH, to sort file by EXIF.

Sort by Renaming

Rare but happened, designer require to sort artwork, such as photograph by the date the picture taken. The idea is using embedded EXIF data. If we can extract EXIF data, we can rename files with almost any EXIF field as suffix. For example using date and time we can rename from this file:

191320.jpg

to this

2020:08:04 19:13:20 191320.jpg

you can automate the task with bash script. And then, it is the file manager job to display in a sorted fashioned.

Check EXIF

Most file manager can obtain EXIF information. Either from file properties, or preview or else.

EXIF in Thunar: File Manager Properties

Extract EXIF Using Imagemagick

There are many ways to extract EXIF, one of them is using imagemagick.

Identify

Extracting EXIF, can be done using imagemagick. You must install imagemagick first. Then run this identify command with verbose option.

$ identify -verbose 121350.jpg
Image:
  Filename: 121350.jpg
  Format: JPEG (Joint Photographic Experts Group JFIF format)
  Mime type: image/jpeg
  Class: DirectClass
  Geometry: 2560x1536+0+0
  Resolution: 72x72
  Print size: 35.5556x21.3333
  Units: PixelsPerInch
  Colorspace: sRGB
...

Imagemagick: identity -verbose

Filtering Information

Yes, we can filter information using pipe in bash. For eaxmple using grep to get any line containg Date.

$ identify -verbose 121350.jpg | grep Date
    exif:DateTime: 2020:08:15 12:13:50
    exif:DateTimeDigitized: 2020:08:15 12:13:50
    exif:DateTimeOriginal: 2020:08:15 12:13:50

Imagemagick: identity, grep Date

Beware with the capital letter in grep, or you may end up with the wrong information.

$ identify -verbose 121350.jpg | grep date
    date:create: 2020-08-18T12:47:25+00:00
    date:modify: 2020-08-15T05:19:38+00:00

Imagemagick: identity, grep date

Now we can go further with just getting the first line.

$ identify -verbose 121350.jpg | grep "exif:DateTime" | head -1
    exif:DateTime: 2020:08:15 12:13:50

Imagemagick: identity, grep, head first line

Automate Renaming Using BASH

Test with one file.

Consider to start from simple script.

#!/usr/bin/env bash

# initialize contstant
prefix="exif:DateTime"
jpg="121350.jpg"

# some unknown magic here
exif=$(identify -verbose ${jpg} | grep ${prefix} | head -1)
echo -e $exif

# whoaa... read the bash manual
datetime=${exif:19:20}
echo -e "[$datetime]"

Name the file as you want such as exif-extract-test.sh. And do not forget to set the executable with chmod +x.

$ ./exif-extract-test.sh
exif:DateTime: 2020:08:15 12:13:50
[2020:08:15 12:13:50]

I’m using bracket box, to check, if there are any spaces that need to be trimmed.

BASH Source in ViM: Extract EXIF from one image file

With the result as below figure:

BASH: Extract EXIF from one image file

Prepare The Case

Supposed we have these folder with a few jpg images.

$ ls -1
121350.jpg
121403.jpg
121405.jpg
121407.jpg
191320.jpg
191322.jpg
191334.jpg
191347.jpg
191355.jpg
191402.jpg
exif-rename-by-datetime.sh

BASH: image before renamed

The Final Script

Name the file as you want such as exif-rename-by-datetime.sh.

#!/usr/bin/env bash

# initialize contstant
prefix="exif:DateTime"

# color
esc=""; purplef="${esc}[35m"; reset="${esc}[0m"

# loop
for jpg in *.jpg; do
  # if not exist
  [[ -e $jpg ]] || continue 

  # do the deed, with imagemagick's identify
  exif=$(identify -verbose ${jpg} | grep ${prefix} | head -1)
  datetime=${exif:19:20}
  
  # carry on, print a fancy notification
  newname="$datetime $jpg"
  echo -e "${purplef}Renaming to${reset}: $newname"
  
  # beware of the space, use double quotes.
  mv "$jpg" "$newname"
done

# cheerio, see you next time

BASH Source in ViM: Running The Script to Rename Image Files

I assume you can get any bash reference yourself.

Running The Script

Consider run the script

$ ./exif-rename-by-datetime.sh
Renaming to: 2020:08:15 12:13:50 121350.jpg
Renaming to: 2020:08:15 12:14:03 121403.jpg
Renaming to: 2020:08:15 12:14:05 121405.jpg
Renaming to: 2020:08:15 12:14:07 121407.jpg
Renaming to: 2020:08:04 19:13:20 191320.jpg
Renaming to: 2020:08:04 19:13:22 191322.jpg
Renaming to: 2020:08:04 19:13:34 191334.jpg
Renaming to: 2020:08:04 19:13:47 191347.jpg
Renaming to: 2020:08:04 19:13:55 191355.jpg
Renaming to: 2020:08:04 19:14:02 191402.jpg

BASH: Running The Script to Rename Image Files

And have a look at the result.

$ ls -1
'2020:08:04 19:13:20 191320.jpg'
'2020:08:04 19:13:22 191322.jpg'
'2020:08:04 19:13:34 191334.jpg'
'2020:08:04 19:13:47 191347.jpg'
'2020:08:04 19:13:55 191355.jpg'
'2020:08:04 19:14:02 191402.jpg'
'2020:08:15 12:13:50 121350.jpg'
'2020:08:15 12:14:03 121403.jpg'
'2020:08:15 12:14:05 121405.jpg'
'2020:08:15 12:14:07 121407.jpg'
exif-rename-by-datetime.sh

BASH: image after renamed

We are done. Have fun with your photographs. Good luck with your designs.

I think this is enough for today. Thank you for reading.