Resize image by largest dimension in Photoshop

Question

I've got tens of thousands of product images that I need to resize (constraining proportions) so that the largest dimension (height or width) is 500 pixels.

The images are in all kinds of sizes, some are perfect squares while most are either tall or wide. I can easily batch resize based on either height or width. The problem here is that if I resize a tall image based on width, it becomes very small etc.

Any ideas on the most practical way to standardize these images so that the largest dimension is 500 pixels?

Answer 1

In Photoshop, Files -> Scripts -> Image Processor.

Enter 500 for both Width and Height and check Resize to Fit. It will maintain the correct aspect ratio and resize the longest dimension to 500.

Answer 2

This DPChallenge forum thread has a Javascript for CS4.
Resize Action in CS3 for portrait OR landscape

Answer 3

This is something Adobe Photoshop Lightroom is MUCH better at. Photoshop will work, as hyperslug explained, but if you plan on doing this a lot in the future you might want to give the free Lightroom trial a spin and see if it saves you some time.