Representng Images

Multiple Choice

What is binary?

• A number system that uses ten digits

• A type of programming language

• A number system that only uses two digits: 0 and 1

• A file storage format

Multiple Choice

Why do computers use binary?

• They prefer it over other number systems

• Because they work with electrical signals that can only be on or off

• It's easier for humans to read

• It helps with image processing

Multiple Choice

What is every digit in binary called?

• Byte

• Nibble

• Bit

• Pixel

Multiple Choice

What is a pixel?

• A type of computer memory

• The smallest unit of a digital image (tiny square)

• A programming function

• A colour format

Multiple Choice

How are colours stored in a computer?

• Using numbers and letters

• As shades of grey only

• In a hexadecimal format

• Using pixels and numeric codes

RESOLUTION:

Resolution refers to the number of pixels in an image, often described as width × height (e.g., 1920 × 1080).

Higher resolution means more detail, but it also increases the file size since more pixels need to be stored.

Open Ended

Name the different ways image can be stored?

Multiple Choice

What is a vector image?

• An image made of pixels

• A type of bitmap

• A photo-editing tool

• An image made of mathematical shapes and lines

Multiple Choice

What is a bitmap?

• A type of animation

• An image made of tiny squares called pixels

• A programming language

• A vector-based image format

Multiple Choice

How does a bitmap work?

• By using formulas to define shapes

• By resizing without losing quality

• By converting images into text

• By storing every pixel's colour information in a grid

Multiple Choice

How are bitmap images stored?

• As mathematical formulas

• As compressed text files

• As a series of pixels with specific colours

• As sequences of shapes and patterns

FILE SIZE CALCULATION:

Bitmap image file using:
File Size (in bits) = Width (in pixels) × Height (in pixels)× Colour Depth (in bits)

Multiple Choice

What happens when a bitmap image is scaled up?

• It stays clear and sharp

• It turns into a vector image

• It changes colour depth

• It gets pixelated and blurry

Multiple Choice

What is resolution in an image?

• The number of pixels in an image

• The size of each pixel

• The colour depth of the image

• The file size of the image

COLOUR DEPTH:

Colour depth refers to the number of bits used to represent the colour of a single pixel.
Examples:

• 1-bit colour depth: Black and white (2 colours).

• 2-bit colour depth: 4 colours.

• 8-bit colour depth: 256 colours.

• 24-bit colour depth (True Colour): 16.7 million colours, with 8 bits for red, green, and blue channels (RGB model).

Multiple Choice

What is colour depth in a bitmap image?

• The number of pixels in an image

• The size of the image file

• The number of colours that can be used in an image

• The brightness of the image

Multiple Choice

What is metadata?

• Data stored in images

• Data that provides information about other data

• The number of pixels in an image

• The file size of an image

Multiple Choice

What is the purpose of hexadecimal in data representation?

• To reduce file size

• To store sound files

• To convert text into images

• To represent colours and binary data more easily

Multiple Choice

What does a 24-bit colour depth mean?

• The image uses 24 different colours

• The image can display 256 colours

• Each pixel is made of 24 bits, allowing for millions of colours

• The image has 24 pixels

Multiple Choice

Which of the following best describes how vector images differ from bitmap images?

• Vector images use pixels, while bitmaps use mathematical formulas

• Bitmap images are faster to load than vector images

• Vector images store colour information for each pixel

• Bitmap images lose quality when resized, but vector images do not

FACTORS AFFECTING IMAGE QUALITY

The higher the resolution, the better the quality.
The higher the colour depth, the better the quality.
The better the quality, the more memory required.