Forum Moderators: not2easy
EDIT: I forgot to mention it includes a plug-in that lets you do lossless compression. I have never used it so I don't know if it's appropriate for your needs.
First you have to create and save a Photoshop action, usually by going through all of the steps on a sample image.
Then you can use Photoshop's Batch Processing feature, found under File > Automate > Batch Process. Select your new action from the drop down list, then choose the directory the images are residing in. Choose the destination of the files (either Close and Save to overwrite the original files, or choose a new directory).
That's it.
[fookes.com...]
If you can do them one by one in PS without a loss in quality then there's something about your optimization settings in the action you've set up to handle batch processing that's affecting the images. Perhaps you're accidentally adding dithering or reducing the number of colors too much.
I second this... It may be a default or batch setting in any given prog you are attempting to use that needs to be changed. Scour your settings before you run the batch.
Then you can use Photoshop's Batch Processing feature, found under File > Automate > Batch Process. Select your new action from the drop down list, then choose the directory the images are residing in. Choose the destination of the files (either Close and Save to overwrite the original files, or choose a new directory).
Or you can make a droplet, basically similar to a batch process. For more advanced automation you can use javascript in 7.0 or CS to write an action but you probably wont need to.