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- Raster Cathode Ray Tubes (CRTs)
- most common
- Capable of high resolution.
- Good colour fidelity.
- High contrast (100:1).
- High update rates.
- Electron beam scanned
in regular pattern of horizontal scanlines.
- Raster images
- are stored in a frame buffer.
- Frame buffers
- are composed of VRAM (video RAM).
- is dual-ported memory capable of
- Random access
- Simultaneous high-speed serial output:
built-in serial shift register can
output entire scanline
at high rate synchronized to pixel clock.
- At each pixel in scanline, intensity
of electron beam modified by the
pixel value being shifted synchronously out of
- Colour CRTs
- have three different colours of phosphor and
three independent electron guns.
- Shadow Masks
- allow each gun to
irradiate only one colour of phosphor.
- Colour is specified either
In the latter case, a colour index is
stored in the frame buffer.
- Directly, using three independent intensity channels, or
- Indirectly, using a Colour Lookup Table (LUT).
Reading: Hearn and Baker, Chapter 2.
Red book, Chapter 4.
White book, Chapter 4.
CS488/688: Introduction to Interactive Computer Graphics
University of Waterloo
Computer Graphics Lab