Image Editing Software

Adobe continues to dominate the category of digital imaging software with Photoshop 4, which is now available for Windows and its native Mac platform. Graphic design at this level is moving into the Windows space but remains a Mac-centric market.

Products in this category aren't intended for a user who just wants to fix a picture. Instead, graphic artists use professional packages, such as Photoshop 4, to create art for commercial publication. Photoshop is a very complicated program, however, and even people who use it regularly often need help in learning how to use it effectively.

File formats Regardless of which type of image-editing software you recommend, it's good to know the common file formats used. Saving files within certain editors is tricky. Users get a choice of file formats and they must decide which one is right for the job at hand.

Universal file formats There are files that can be opened on any platform that are referred to as universal file formats. TIF, JPEG and GIF are universal. GIF and JPEG are also the standard image file formats for the World Wide Web. Photographic images with continuous tones-24-bit color or 8-bit gray (which yields black, white and 254 shades of gray for a 256-color palette) and no text-are best saved as a JPEG if file size matters.

JPEG, an acronym for Joint Photographic Experts Group, is an efficient format because it compresses the image. It is what's called a lossy format, meaning it will dump whatever bits it can to reduce the file size. If users open and re-edit a JPEG file, they lose a little more information each time. It's the nature of the format.

TIF, or Tag Image File format, also works for these types of files but is considered to be the best format for scanned images. It's also good for graphics, logos or text files. The trade-off is that TIF files are enormous and could take more hard-disk space than many pictures warrant. Also, JPEG files can be e-mailed; TIF files are usually too large.

GIF, or Graphic Interchange Format, is a small, compressed format. It is limited to 256 colors and is a lossless format. Users can't save a file as a GIF until the colors have been reduced to 256 or fewer. Essentially, the file can use any 256 colors from the 16.7 million color palette of a 24-bit image.

If users are working with GIF files for a Web site, tell them that it's best to use the same palette for all the files posted to a site. Also, Netscape uses its own palette, which can be found on its Web site and several other places online. It is called "6-6-6," with six options for each color (red, green, blue). Thus, there are only 216 colors for the Netscape palette.