Finder shows executable shell scripts as Unix binaries

This won't work for a signed app, but here's how I was able to get this to work:

1. Create a copy of the app you're trying to modify in case something goes wrong. (⌘D in Finder) For my example here, I modified the non-app store version of VectorDesigner

2. In Terminal, cd /Applications/VectorDesigner.app/Contents/MacOS

3. mv VectorDesigner VectorDesigner\ copy (substitute the name of your app here

4. pico VectorDesigner (or your editor of choice) and add the contents of your script.

   I used this script

    #!/bin/sh
    osascript -e "tell Application \"Finder\" to display alert \"Hello World\""
    /Applications/VectorDesigner.app/Contents/MacOS/VectorDesigner\ copy
   

   The important thing is for the last line to call the renamed executable.

5. chmod a+x VectorDesigner

Now, when I double-click the VectorDesigner icon, I get the "Hello World" window, then it launches the original program.

I would just do the whole thing at the command line as a shell script instead of using Automator to launch it. Put #!/bin/bash as the first line, and run it as

myscript.sh image*.png

where image*.png is your set of image files that you are apparently selecting in Automator?

If you need to run it on all files in a folder, that can be done too.

You can also test your script in automator using echo ${f%.*} instead of the commands themselves.