Data Representation Flashcards
What is ASCII?
- Uses seven bits, giving a char set of 128.
- This includes lower case, upper case, punctuation, numbers
What is UNICODE?
- Universal code
- Uses 16 bits giving over 65000 chars.
- Suitable for languages other than English and allows symbols specific to languages.
How does binary shift work?
left = multiply
right = diivide
X or / by 2 = one place to left or right
X or / by 4 = two places to left or right
X or / by 8 = three places to left or right
What is UNICODE?
- Universal code
- Uses 16 bits giving over 65000 chars.
- Suitable for languages other than English and symbols specific to languages.
How does binary shift work?
left = multiply
right = diivide
X or / by 2 = one place to left or right
X or / by 4 = two places to left or right
X or / by 8 = three places to left or right
How does Huffman coding work?
Its lossless compression and is good in situations where you use a string multiple times.
Why must sound be converted?
To convert an analogue signal into a digital one for storage
How does a bitmap present an image?
A series of pixels.
What does increasing pixels do?
Increases the resolution of the image.
What do binary numbers represent in an image?
A single colour.
How can you present a greater range of colours?
Use a greater range of binary numbers.
What is sampling?
A method of converting an analogue sound into binary numbers that are then stored in a digital file.
What is sampling rate?
Number of samples taken per second.
What is sampling resolution?
The number of bits to represent each sample.
How do you work out the file size?
Length x sample rate x sampling resolution.
