C1.2 Text, Sound, and images

Why does a computer use of character sets?

To convert human-readable text, symbols, and numbers into binary code that computers can process, store, and communicate.

How is text converted into binary by a computer?

By assigning every character a unique numerical code using standardized encoding systems like ASCII or Unicode

How many bits does ASCII code use?

The ASCII uses 7 bits to encode characters, meaning it can represent 128 different characters

How many bits does Unicode code use?

Unicode was developed to use 16 bits, which means it can represent 65,536 different combinations.

How does a computer represent sound?

Analogue sound is converted to digital by taking measurements of the sound wave at regular intervals. These measurements are then converted into binary. This process is called sampling.

Define sample rate and sample resolution

Term	Essential Exam Description
Sample Rate	number of samples taken in a second
Sample Resolution	number of bits per sample

How do sample rate and bit depth (resolution) influence the accuracy and storage requirements of a sound file?

The accuracy of the recording and the file size increases as the sample rate and resolution increase.

What is a pixel?

A pixel (picture element) is the smallest identifiable piece of an image.

How do computers represent images?

Computers represent images by breaking them down into pixels . Each pixel is assigned a specific binary number that represents its color.

Define resolution and colour depth.

Term	Essential Exam Description
Image resolution	number of pixels in the image
Colour depth	number of bits to represent each colour

What happens if resolution and colour depth increase?

The file size and image quality increase.