Software to losslessly optimize batches of image files I frequently work with large numbers of image files to be used in websites.

I'm currently using Photoshop's 'Save for Web' tool to find the most efficient way to compress images, but that takes some time and isn't always perfect.

I'd love to find a nice utility that can automatically go through my images and optimize each one.

Requirements:


Compression should be lossless.
Utility should be able to chug through a batch process automatically (i.e. without me interacting with it for each image).
Should support JPEGs* and PNGs, and ideally GIFs.


The app does not have to be free, as long as it's good.

*By JPEG support I mean reducing file size without making the compression any more lossy than it already is (throwing out metadata, etc).
ImageOptim?

ImageOptim optimizes images — so they take up less disk space and load faster — by finding best compression parameters and by removing unnecessary comments and color profiles. It handles PNG, JPEG and GIF animations.
ImageOptim seamlessly integrates various optimisation tools: PNGOUT, AdvPNG, Pngcrush, extended OptiPNG, JpegOptim, jpegrescan, jpegtran, and Gifsicle.