Text, Sound & Images Flashcards
(21 cards)
Define Character Set
Defined list of characters that can be understood by computers.
What is ASCII?
A character set that uses 7 bits
What is the definition of extended ASCII
ASCII character sets that uses 8 bits
Define UNICODE
a character set that uses a minimum of 16 bits.
State the meaning of bit
A single binary digit representing either 0 or 1
What does character encoding mean?
The process of assigning a unique binary code to each character in a character set.
Define sampling
Process of measuring and capturing values of an analogue signal at regular intervals.
Define sample rate
the amount of samples taken per second
State the meaning of sample resolution
Number of bits stored per sample of the sound.
Define digital
Data represented as a series of discrete values.
Define bitmap
An image made up of squares called pixels.
Define pixel
The smallest element of a bitmap image
Define resolution
The total amount of pixels that make up a bitmap image.
What does color depth mean?
The number of bits stored per pixel.
What is the meaning of true color?
A color depth of 24 bits
Define metadata
Data about data
Give one example of an image format
JPEG
Describe how a digital image file is stored by a computer.
Images are made of pixels and each pixel stores one color, each color has a unique binary value.
State what is meant by data compression?
Reducing the file size
Explain why someone would compress a digital image file before emailing it
Reduces storage space taken on email server, and sending email accounts may have restricted file size for attachments.`
