Unlike bitmap images, object-oriented (or vector) graphics are made up of whole objects, such as lines, arcs, circles, and boxes (Figure 23). Object-oriented graphics are also called vector graphics because they’re stored by the computer as mathematical formulas describing the objects that make up the image.

Object-oriented graphics are considered superior to bitmap graphics because the quality of the final image is dependent on the quality of the printer used. The higher the resolution the printer is capable of, the better the printed file will look. By comparison, bitmap images have a fixed resolution that isn’t improved by printing on a higher quality: If your bitmap is 300 dpi, it will print at 300 dpi, even when printed on a 2400 dpi imagesetter. Because an object-oriented graphic is actually a set of instructions to the printer describing a group of objects, it can be resized without loss of definition or distortion. Figure 24 compares the relative distortion of object-oriented and bitmap graphics. Notice that the lines in the object-oriented figure maintain their original smoothness as the image increases in size. In the bitmap image, these lines develop more jaggies as the image gets larger. The main disadvantage of object-oriented graphics is that the programs that use them are often more difficult to learn and use.

Three common formats for object-oriented graphics are Encapsulated PostScript (.EPS), CorelDRAW! (.CDR), and Adobe Illustrator (.AI).

	Created by ren -_- about 5 years ago

Computer Graphics Formats - Bitmap Graphics