Physics Ch. 15 & 16 Flashcards
Composed of 2 shades, black and white
bistable images
Gray scale displays multiple
levels of brightness: white, black and gray
What are the two display user controls for video monitors
contrast, brightness
Determines range of brilliancies within displayed image
contrast
Bistable images are _____ contrast
high
Gray scale images are _____ contrast
low
Determines brilliance of the displayed image
brightness
Store information and display it
scan converter
Used in early days of two-dimensional imaging
analog scan converter
Used in modern day A-D imaging
digital scan converter
Can have an unlimited and continuous range of values
analog numbers
Discrete values
Digital numbers
Spatial resolution (imaging detail) of an analog scan converter is
excellent
Limitation of analog scan converter
image fade, image flicker, instability, deterioration
Use computer technology to convert images into numbers
digitizing (1s and 0s)
Advantages of digital scan converters
uniformity, stability, durability, speed, accuracy
Two important elements of digital scan converters
pixel, bit
Picture element, smallest building block of a digital picture
pixel
Number of pixels per inch
pixel density
Higher pixel density is achieved with
smaller pixels (more pixels per inch)
What improves with high pixel density and creates an image with greater detail
spatial resolution
Binary digit, smallest amount of computer memory, bistable
bit
Group of bits and a series of 0s and 1s, digital
binary number
A group of 8 bits of computer memory
byte
Computer memory that consists of 2 bytes
word
Many shades of gray have better
contrast resolution
How many shades of gray are displayed with 5 bits of memory
32
Converting information from analog to digital is advantageous because
digital information is far less susceptible to contamination
What is the 5 step process from analog to digital
- A-to-D converter, 2. preprocessing, 3. post processing, 4. D-to-A converter, 5. Analog form is displayed
Manipulation of image data BEFORE storage in the scan converter
pre processing