Unit 1 Data Representation Flashcards
How is:
Sound recorded
- As an analogue wave
- Converted into digital format
- Done by Analogue to Digital converter(ADC)
How is:
Sound measured
- Sound wave is split through sampling
- measurements are taken through wave height
- This is done at regular intervals
- stored in binary
What is:
Sample rate
- Sample rate is samples/second
- Measured in Hz
What is:
Bit depth
Number of bits defining each pixel
What is:
Bit rate
data processed per second of sound
Formula for size of a:
Sound file
bit rate * time
Formula for an:
image
pixel resolution * colour depth * folder size
What is:
Data about an image
Meta data
What is:
meta data
information about a particular image
e.g. colour depth and pixel resolutio
What is the use of:
Hexadecimal
easier to read than binary
MAC address is in hex
How are:
Negative numbers stored
Through 2’s compliment
Do some practice
Some registers store negative numbers
What is:
Overflow error
Where there are not enough bits to store a calculation, so data is lost
How are:
Images created
Through a lot of individual pixels which have different colours by having a different shade of green, red and blue
What is:
ASCII
- American Standard code for information interchange
- uses 7 bits
- stores 128 different characters
- new extended version is 8 bit
What is:
Unicode
- stores all possible characters/keys on a keyboard
- over 65,000 storage capacity
- 16 bits
What is a:
Binary shift
If all the 1s of a binary number are shifted left, the number doubles
Opposite applies as well
What are the different:
Units for storage
Bit
Nibble (4bits)
Byte (2 nibbles)
Kibibyte (KiB) (1024 bytes)
Mebibyte (MiB) (1024 KiB)
Gibibyte (GiB) (1024 MiB)
Tebibyte (TiB) (1024 GiB)
Pebibyte (PiB) (1024 TiB)
Exbibyte (EiB) (1024 PiB)
What is:
Compression
Reducing the size of a file
What is:
Lossy compression
- Removing unnecessary data
- Can lead to a lower image quality
- e.g. decreasing an image resolution or removing sounds above 16500Hz
What is:
Lossless compression
- Compression where no data is loss
- Works by using an algorithm which re-writes the data in a more effective way e.g. Run Length Encoding which re-uses data at specific intervals
- Original file can then be retreived by decoding the file algorithm
What is:
Sample resolution
Number of bits used to describe the amplitude of a wave
