Graphic Systems Flashcards
How do CRTs work?
Horizontal and vertical deflectors focus an electron beam on any spot on a phosphor coated screen.
What is fluorescence?
A photon of light emitted from phosphors returning to ground state, decays in under a millisecond.
What is phosphorescence?
The light emitted by phosphors that get further excited, decays in 15-20 milliseconds.
What is persistence of phosphorus?
The amount of time it takes for the phosphorus to decay to 1/10th its intensity.
How do CRTs get different colors?
They have 3 electron beams, one for each Red, Green, Blue. Used in different combination.
What is a shadow mask?
A plate with holes to help focus the electron beams on the correct phosphorus and prevent bleed.
What does an LCD consist of?
A reflective mirror, glass with polarizing film, electrode plate, liquid crystal, another plate, polar film at right angle to previous.
Reflective vs. Back-lit LCD?
Calculator vs. Monitor.
Passive vs. Active LCD Matrices?
Passive needs constant refresh, Active does not due to capacitors.
3 bytes for color is how many colors?
16.8 million = 256 x 256 x 256
What is a raster?
A matrix of pixels.
What is a bitmap?
aka pixel map, is an array of numbers representing pixels.
What is the memory requirement of a frame?
Resolution * pixel bits + look up table
Whats run length encoding?
Save memory by not repeating pixel values that are the same, just list how many.
What is a color look up table?
A table that is smaller than the total colors, this reduces the pixel bits size and allows for color depth at the cost of less colors.
What’s rasterization?
When an image of pixels gets mapped.
What is Anti-Aliasing?
Using softer colors around pixels to make lines appear smoother.
