Tom called the radio show about digital photography, and we discussed format preferences…here’s what I think I know:
There are two basic kinds of computer graphics: raster (composed of pixels), and vector (composed of paths).
Most of the time it is best to use the vector format for all type, line art, and illustrations. Bitmaps are considered best for photos or images…
Vector graphics are best suited for page layout, type, line art, or illustrations. You can increase and decrease the size of vector images to any degree and your lines will remain crisp and sharp, both on screen and in print. The primary disadvantage is that they’re unsuitable for producing photo-realistic imagery. They tend to have a cartoon-like appearance.
At this time, the most common and accepted format for vector images on the Web is Shockwave Flash (SWF). Another standard for vector images on the Web is SVG
Due to the nature of vector images, they are best converted to GIF or PNG format for use on the Web.
Raster images are more commonly called bitmap images. A bitmap image is composed of pixels. Pixels can be of differing colors. Most bitmap formats are TIFF, PCX, and BMP.
For web pages:
GIF – Graphics Interchange Format – The GIF format uses compression for smaller files and faster downloads.
JPEG – Joint Photographic Experts Group – the JPEG compression can be “lossy”…save the image using no compression or “lossless” compression and make JPEG copies from it.
For printed documents:
TIFF – Tagged-Image File Format – Used for bitmaps only. The TIFF format is supported by virtually all graphics applications.
EPS – Encapsulated PostScript – A file format used for both vector graphics and bitmaps. EPS files are unique in that you can use them for vector graphics, bitmap images, and type.