2. RASTER SYSTEM ?
The raster graphics developed in early 70’s.
It is commonly used in CRT monitor.
It is based on TV technology.
In this system, electron beam swaps across
the screen one row at a time form top to
bottom.
Beam intensity vary (on or off) by the
movement of electron beam across each
room.
Picture definitions are stored in refresh buffer
5
3. buffer which holds the setup intensity values for
all the screen point also known as pixel. (pel)
Stored intensity values are retrieved form the
refresh buffer and painted on the screen on scan
line (one row at a time).
The refresh rate for this system is at the rate of
60 to 80 frame per second.
7. Architecture explanation..
Interactive raster graphic generally employ
several processing units.
In addition to the CPU a special buffer
processor called video controller or display
controller is used to control the operations
of display device.
8. Architecture explanation..
Frame buffer can be any where in the
system memory, and the video controller
accesses the frame buffer to refresh the
screen.
A fixed area of system memory is reserved
for the frame buffer.
Video controller direct access the frame
buffer.
