The ability to convert images from one format to another with minimal retouching and manipulation is built right into Mac OS X.
Every so often — but not often enough to warrant shelling out for a full-scale draw or paint program — I find myself needing to convert an image from one format to another. Perhaps I have a photo in TIFF format I’d like to incorporate into my web site as a JPEG or GIF. Or I need to share a screenshot with a Windows user who prefers BMP to PNG.
Thankfully, OS X users have some minimal functionality for image conversion and alteration built right into their OS.
Preview takes me back to the days when a web browser became a launchpad for a plethora of helper apps, specialized viewers for images, movies, or sounds. It’s the helper you always wished for for all things image, able to open, save, and convert PDF, JPEG, TIFF, PNG, and others, as well as to export a Photoshop image as a GIF, a Windows BMP to Quicktime, or a fancy new PNG to old faithful MacPaint.
Open an image via File → Open,
-O, or double-clicking an image file or dragging and dropping it to Preview’s Dock or Finder icon. Choose File → Export . . . , pick an output format, and save. For a mite more fine-tuning, click the Options . . . button in the Save sheet to set color depth, simple filtering, interlacing, and the like, as shown in Figure 3-13.
Figure 3-13. Exporting ...