Automator can resize images to a percentage or a specific pixel size.
To do this follow the following steps:
1. Open the Application Automator.app.
2. Make sure that the "Applications" folder is selected in the left column of Automator.
3. Type "Get Specified Finder Items" in the upper left box of Automator to search for the action.
4. Drag the action "Get Specified Finder Items" to the right side of the screen where it says "Drag or add actions here to build your workflow.".
5. Now search for "Scale Images" in the top left box of the Automator Application and select the "Scale Images" action.
6. Drag the "Scale Images" action to the right side of the automator under the "Get Specified Finder Items" action.
7. I'd recommend clicking the "Add" button if a dialogue box appears so that your original image isn't replaced with this smaller inferior one that Automator will create. I do recommend however having a back-up copy of your own (of the image) available in case automator fails to make a copy of the image. I think Automator may have overwritten a picture of mine once or twice even though I told it to make a copy with the "Copy Finder Items" added action.
8. Press the plus button on step one (which should be "Get Specified Finder Actions") of your workflow (the workflow is the list of actions that you put on the right side of Automator) and browse for your picture and select "Open".
9. On step 2 of your workflow tell automator where you want it to save the scaled picture ("Desktop" should be the default location).
10. On step 3 of your workflow tell Automator if you want it to scale your image "By Percentage" or "To Size (pixels)" and type in the number for the percentage or the pixels.
11. Press the "Run" icon (a triangle in a circle--it looks like a standard video "play" button) in Automator.
This should make your new picture just the way you want it and put it in the location that you told Automator to put it in step 2 of your workflow.
I've used this type of workflow at least twice so it might be a good one to save and use in the future. I hope this helps.
