Data Representation Flashcards
How do computers store integer numbers?
Two’s compliment
How do computers store real numbers?
Floating Point Representation (FPR)
What is FPR made up of?
The mantissa (the significant figures of the number) and the exponent (which holds the power)
Explain how increasing the number of bits affect both the mantissa and the exponent
Increasing the number of bits assigned to the mantissa increases the ACCURACY an increasing the bits to the exponent increases the RANGE of numbers. Remember MARE
How is text stored in a computer?
Using a binary number code to represent each character
How many characters can ASCII represent?
2^7 = 128
How many characters can Unicode represent?
2^16 = 65536
What are bit-mapped graphics?
Bit-mapped graphics are where every pixel in a 2D grid is stored in memory as a bit or a group or bits.
What is the bit-depth?
It’s the number of bits required to store the colour of each pixel.
Describe resolution
The resolution is the size of pixels, commonly measured in dpi
What are vector graphics?
Vector graphics are where each object making up the image is stored in a list of attributes.
What do the attributes of vector graphics describe?
They will describe an object e.g. the centre X/Y co-ords, radius, line thickness, line depth
Give five differences between bit-mapped and vector graphics.
- Bit-mapped graphics have larger storage requirements
- Bit-mapped graphics are resolution dependent and will become pixelated when bigger
- Bit-mapped graphics allow you to change individual pixels
- Vector graphics allow you to isolate and change an individual object
- Vector graphics allow you to layer objects in different orders
What is stereo sound?
Stereo sound will actually store samples for two waves
How is the sound quality determined?
By the sample rate and sample depth
