If you are looking for a free, but full-featured, image editing program for OS X systems, GNU Image Manipulation Program (GIMP), which is available for Linux, Solaris, and even Microsoft Windows operating systems, also, is available for OS X. Mac OS X versions can be downloaded as .dmg Apple Disk Image files.
GIMP's native image format is eXperimental Computing Facility (XCF), but it also provides import and export support for image formats such as BMP, GIF, JPEG, PNG, and TIFF, along with the file formats of several other applications such as Autodesk flic animations, Corel Paint Shop Pro images, and Adobe Photoshop documents. Other formats with read/write support include PostScript documents, X bitmap image and Zsoft PCX. GIMP can also read and write path information from SVG files and read/write ICO Windows icon files.
