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Glossary of Physics Chapter 15-US

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Created by huffmajl

in the DISPLAY, The ______are fired by the electron gun.
electrons
After the electrons are fired by the electron gun, they are sent through the _____
magnetic field
After the electrons are sent through magnetic field the phosphors ____
glow when electrons hit them
Together the even and odd field are interlaced reducing
flicker creating a frame
The Tv screen is made up of ___ closely spaced horizontal lines
525; they are swept with line scans
bi means
2

bistable=
black and white
grayscale =
multiple levels of brightness
found on the monitor
display controls
range of brilliancies within display
contrast
black and white images
high contrast
many gray shades
low contrast
determines the brilliance
brightness
what makes grayscale
scan converters
a scan converter ____then ___
stores then displays
to store is called
writing
to display is called
read
a scan converter translates info from ____format to ___format
spoke to video
what converters do we use today?
digital scan converters
real numbers are ___
analog
continuous; unlimited
analog
used in computers
digital
use discrete values; limited choices
digital
original scan converter
analog scan converter
made grayscale possible
analog scan converter
with the analog scan converter...vacuum tube with electron gun, electrons are set to silcon wafer or _____ot be stored in an _____
dielectric matrix; electron bucket
with the analog scan converter there is excellent ___resolution
spatial
Limitations of analog S. Converters
image fade
image flicker
instability
deteriation




used in computer technology
digital scan technology
images converted to ____and ____ with the digital scan converters
1's and 0's
with the digital scan converter, it is ____or digitized for display
retranslated
advantages of digital scan converters
uniformity
stability
durability
speed
accuracy



2 elements of digital scan converters
pixel
bit
pixel stands for
picture element
single shade of gray
pixel
number of elements per inch
pixel density
smaller pixels, more pixels
high density
improves with high density, better detail
spatial resolution
binary digit
bit
smallest amount of memory assigned to pixel
bit
0 or 1
bistable
8 bits of memory
byte
series of 0s and 1s
binary number
regular numbers 0-9
decimal numbers
2 bytes or 16 bits
word
more bits, improves ___ ____
contrast resolution
calculating the number of gray shades
2 number of bits
A and D Data
During reception.

analog is converted to digital for _____


storage
occurs in digtal format before storage (TGC, log compression, write magn)
preprocessing
occurs after storage in digital scan converter ( after freeze, black/white inversion, read mag, contrast variation)
post processing
Digital signals translated back to analog for display on TV
digital to analog
signal on TV monitor is in analog called
video display
TGC, log compression, write mag are examples of
preprocessing
black/white, read mag, contrast variations are examples of
postprocessing
example of both post and pre
persistence ; frame averaging; edge enhancement; smoothing; fill in interpolation
region of interest is enlarged
magnification
2 types of zoom
read and write
after image is stored or frozed
read
same number of pixels lines as original
read
larger pixel size
read
not rescanned
read
spatial res is unchanged
read
during data acquistion
write
before frozed
write
rescans
write
number of pixels is greater than original
write
pixels stay the same
write
digital images stored on a large comp network
pacs
advantages of pacs
instant access; no degradation; transmits images to others
combo of magnetic laser technology
magnetooptical storage
stores large amounts of data
magneto-optical storage

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