Convert an image to base64 data URI that's then copied to the clipboard.

img2datauri.sh

#!/bin/bash

# Create a base64 data URI from an image and copy it to clipboard.
# Uses OpenSSL to create the base64 representation.

the_mimetype=$(file -bN --mime-type "$1")
the_content=$(openssl base64 < "$1" | tr -d '\n')

# Use printf instead of echo to avoid the ending newline
printf "data:$the_mimetype;base64,$the_content" | pbcopy

To Use

1. Download this script into a folder that will contain images.
2. Open a terminal window and cd into the folder.
3. Make this script executable by typing chmod +x img2datauri.sh.
4. Execute by typing ./img2datauri.sh image.png. Replace image.png with proper filename. Data URI can then be pasted into browser dev tools to see the new image.