chapter 3--Data representation Flashcards
What do you call it when the value that is computed cannot fit into the number of bits we have allocated for the answer?
overflow
WhAt are the first 256 characters of Unicode?
The ASCII extended charset
What type of encoding replaces frequently-used words with a single character?
keyword encoding
True/False. Run-length encoding is very good at compressing English text.
false.
What kind of encoding uses variable-length binary strings to represent characters?
Huffman encoding
True/False. The MP3 format discards information that cannot be heard by humans.
true
What does MP3 stand for? Also, describe the encoding process
MPEG-2, audio layer 3 file. Moving Picture Experts Group, an international committee that develops standards for digital audio and video compression. First, info that humans can’t hear is discarded, by comparing the file to mathematical models of of human psychoacoustics. Finally, the bit stream is compressed using a form of Huffman encoding.
How does the RGB model represent color?
Using 3 number values for red, green, and blue. 0 to 255 for each.
True/False. Bitmap, GIF, and JPEG are all examples of raster graphics formats.
true
How do vector graphics represent images?
in terms of lines and geometric shapes
True/False. A keyframe is used in temporal compression to represent the changes from one frame to another.
false. delta frame
What kind of data is a continuous representation of information?
analog
the representation for numbers you’ve used since grade school is called ______.
signed-magnitude representation
if the number system is other than base 10, we call the decimal point the ______
radix
_______ data is a discrete representation of information.
digital
Huffman codes are created based on the _____ of the character.
frequency
What is pulse-code modulation?
the way in which digital data is transmitted. it’s a square wave, that is either on or off at any given point in time, which corresponds to either a 0 or a 1.
The GIF format uses which technique?
Color indexing
What do we call the perception of the various frequencies of light that reach to retinas of our eyes?
Color
What is the best format for photographic color images?
JPEG
What are the video compression techniques?
Codecs, both spatial and temporal
What is the technique in which an application supports only a certain number of specific colors, creating a palette from which to choose?
Color indexing
Which format stores information on a pixel-by-pixel basis?
Raster graphics format
What is the difference between HiColor and TrueColor?
HiColor is 16 bit, and TrueColor is 24 but
