Nothing's ever quite the way you want it. Just ask Goldilocks: chairs, breakfast, beds, nothing really worked for her. If you've got a pile of image files, you may be familiar with that concept. This picture is too big; this one is too small. Fire up Photoshop to fix them, and you're committing to a long, hard slog—as well as several bills—to get the job done. Faster and cheaper might be nice.
Pixer is a Mac tool that lets you tweak your graphics files. Choose an individual file or a whole folder full, drag them onto the app, and let go. Choose how you want them resized—you can specify a pixel number, percentage, or choose from presets for specific sizes, as well as being able to rotate and flip images, or crop and pad them. It supports most popular image formats, so you can probably use it for whatever you're working with.
Pixer is a free download for Mac users. You'll need to be running at least version 10.4 of OS X (10.5 for some advanced features) to use it.
Download Pixer
