How to automate some picture manipulation (define a crop and apply a crop) in photoshop?

Question

I am currently working on a lot pictures (around 1000) and would like to automate some tasks:

1. define a crop region that correspond to specific aspect ratio. For example if i have a width/height = 16/9 i need to find the best fit in an image that can hold this aspect ratio.
2. crop the image.
3. save the image as a png file.

can i automate this in photoshop or lightroom with a minimum of user interaction? Is there some better alternative than photoshop or lightroom to realize this task?

Answer 1

You can automate most tasks in Photoshop by using actions. You can record them, enter them by hand or download others from the internet. They can be fully automated with predefined values or you can design them to ask for settings when they run. Short tutorial

I don't think you can automate tasks in Lightroom and I don't have any experience with other alternatives, but I'm sure there are many.

Answer 2

In addition to Olle Sjögren's great suggestion (Actions are brilliant for this kind of thing), OS X's Automator can be used. It's free, and already in your Applications folder if you're a Mac user.

And... if you're willing to type some stuff into Terminal/CLI, ImageMagick can batch process images to do pretty much anything.

Your options are:

• Actions and batch processing in Photoshop (OS X and Windows).
• OS X's Automator (OS X only).
• ImageMagick (OS X, Windows, Linux).

There's other ways to do it, too, but those are good ways to go.