Launch Automator and do something like this CC:
ClickyFind the first item under "Finder" on the far left and drag it to the left, then you can see what I chose for converting to PDF.
Save as follows:
File > Save as plug-in...
Make sure Finder is selected and give it a name...
Use the script by selecting(highlighting) the image icons, ctrl-click > more > automator > script-name
You may like to play with the settings

HTH
