U4 - GRAPHICS & SOUND

Boolean Float / Real Integer Character String

Raster images are made from a dot matrix of data representing a grid of pixels

• Pixels can be individually edited • Lose quality when scaled up • Take up more storage space

• Graphics made using mathematical formulas • Popular in logo design

• Can be scaled up without a loss of quality • Smaller amount of memory needed to store • More complicated to make

• The number of dots/ pixels per inch (dpi) • The greater the image the more defined an image is but also more file space needed

Colour Depth x Img Height x Img Width

How many bits a colour pixel is

24 BITS (RGB Colour Sliders)

Computers cannot understand analogue sound. It must be converted into discrete digital data through sampling

The amplitude of an analogue sound is sampled at set intervals and recorded as digital data.

The number of times a sound is sampled per SECOND (Hz)

Number of bits used to store each sample.

How many seconds of audio in a file

Sample Rate (Hz) x Bit Depth (bits) x Duration (s)

American Standard Code for Information Interchange

Standardised character sets allow for data interchange between different programs

7 bit

Uses 32-bit in order to represent all language characters Original 128 ASCII characters are the same Unicode uses more memory to store a character

PRESENCE CHECKS FORMAT CHECKS LENGTH CHECKS TYPE CHECKS RANGE CHECK

Prevents further progress if a required field is left blank

ENSURES DATA MATCHES A SPECIFIC PATTERN i.e dd/mm/yyyy

Used to ensure input data is a sensible length .i.e. First name is between 3-16 characters

Ensures inputted data is the correct data type