Desktop Color
Introduction
Desktop color
Memory
Some of you have a computer system for a workstation. You should become
familiar with color as it applies to computer-generated or desktop color.
Desktop color is computer-generated color or various shades of grey from an
IBM (PC) or Macintosh (MAC) computer systems. The color limitations of
desktop color are the Random Access Memory (RAM) capacity of the
computer, the Video Graphics Array (VGA) card, the scanner, and the
monitor.
Random Access Memory (RAM) determines the speed and power
considerations for color. Color displays require more RAM than
monochromatic displays. If your computer doesn’t have enough memory,
you will experience delays in completing jobs that involve color. When
adding color capabilities to your desktop system, reevaluate memory capacity
and expand it if necessary.
Video Graphics
Array (VGA)
Video graphics array (VGA) cards or Super Video Graphic Array (SVGA)
cards control the resolution of computer monitors. Monitor resolution is
stated in terms of dots per inch (dpi) for MAC monitors or picture elements
(pixels) for PC monitors. You may use a VGA with color or black-and-white
monitors. The VGA monitor has a resolution of 640 x 480 dpi. Super VGA
increases the resolution to 800 x 600 dpi or 1024 x 768 (extended VGA).
Scanners
Scanners scan text and images and record them to memory. The type of
scanner determines the resolution of the scanned image. Scanners are
classified by image capture capabilities and whether they use the theory of
reflectance (opaque copy) or the theory of transmission (transparent copy).
There are hand-held scanners, sheetbed scanners, flatbed scanners, overhead
scanners, slide scanners, and drum scanners.
Most scanners connected to
desktop computer systems use sensing elements called charged-couple devices
(CCD). When light strikes CCDs, they retain voltage. The voltage
apportions the amount of light striking the sensors and transfers this into
reproduced copy. CCD scanners are of lower resolution than the
photomultiplier tube scanners of Color Electronic Pre-press Systems.
Continued on next page
2-36
