Software for resize DPI in bulk?

Hi,

I'm looking to decrease the DPI for around 400-600 images. What software would you recommend I use to do this in bulk?

iPhoto doesn't seem to be able to and that's the only image editing software I've got.

I know DPI changed be changed in Preview, but seemingly one image at a time.

All help appreciated!

John.

I found this, hope it helps

Access hidden Preview features through Automator | Preview | Mac OS X Tips

That article is 3 yrs old and references Tiger. But Automator is still a good solution to batch changes. I'm sure it's not the only one, but it will work.
I suggest using Automator to create a folder that will open Preview, resize, and save files to a specific folder when you drop files into it. You could take 100 image files, drop them into that folder and it'll automatically do the rest. You just have to set it up properly. It's pretty intuitive and if you need any help, use the Help in Automator or Apple's support page. apple.com/support

GraphicConverter was built to do exactly this sort of stuff.

Thanks for all of your help! Automator worked fine.