← Issues in Technology

How images are made of numbers

A tiny square of colour that images are built from, stored as RGB numbers in binary.

Part of: Investigating Issues in Technology — Module 6, 7-8 Digital Technologies: Representing data with binary — Module 17, ACARA Digital Technologies Years 9–10 — Data Compression — Module 5

Understanding How images are made of numbers in Issues in Technology

What it does: Resolution describes how much detail an image can show. Every pixel's colour is stored as binary numbers. Every digital image is a grid of tiny coloured squares called pixels. More pixels pack in more detail, raising resolution. Bigger images actually need more pixel data, not less. Resolution is directly tied to how many pixels an image has. A pixel is the basic building block of a digital image. RGB values combine to create each pixel's exact colour.

Common mistakes: Images do have pixels - they're made up of many of them. Colour data isn't meaningless - it defines each pixel's colour.

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This module's key terms are also in a printable crossword (Part 1 of 2) and word search (All modules).

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Learning
Duo
Are digital images made up of pixels?
YesNo
Matches
Images have no pixels at all
↓
Wrong - images are made of many pixels
Applying
Meanings
Term
Pixel
Meaning
A tiny square of colour that images are built from, stored as RGB numbers in binary.
Practice
Images are made of pixels.
Testing
Gaps
Images are made of
Check Answer
Spots
1Images have no pixels
2Each pixel has a colour

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Quick Questions

1. Are digital images made up of pixels?
A. Yes ✓
B. No
Every digital image is a grid of tiny coloured squares called pixels.
2. Does each pixel have a colour value?
A. Yes ✓
B. No
Every pixel stores a colour, usually as RGB values.
3. Does RGB stand for red, green and blue?
A. No
B. Yes ✓
RGB combines red, green and blue to make every pixel's colour.
4. Do more pixels usually mean higher resolution?
A. No
B. Yes ✓
More pixels pack in more detail, raising resolution.
5. Are pixel colours stored as binary numbers?
A. Yes ✓
B. No
Computers store every pixel's colour as binary numbers.

Match the Pairs

Pixel → A tiny square of colour that makes up an image
RGB → The red, green and blue values that create a pixel's colour
How images sharpen with more pixels → Resolution
How pixel colours are stored by computers → Binary numbers
Images have no pixels at all → Wrong - images are made of many pixels
Pixel colours are stored as plain text → Wrong - pixel colours are stored as binary numbers

Key Term

Pixel
A tiny square of colour that images are built from, stored as RGB numbers in binary.

Fill in the Blanks

1. Images are made of pixels
Hint: Type the word for the tiny squares that make up an image.
2. Each pixel has a colour value
Hint: Type the word for what a pixel shows.
3. Colours are stored using RGB values
Hint: Type the three-letter name for red, green and blue values.
4. More pixels give higher resolution
Hint: Type the word for the sharpness of an image, based on pixel count.
5. Pixel colours are stored in binary
Hint: Type the word for the number system computers use to store data.

Spot the Error

Question 1
A Images have no pixels
B Each pixel has a colour
C Colours are stored in binary
Line A — Images do have pixels - they're made up of many of them.
Question 2
A Pixels make up an image
B Colour data means nothing
C RGB stores colour values
Line B — Colour data isn't meaningless - it defines each pixel's colour.
Question 3
A Each pixel has a colour
B RGB stores colour values
C Pixels are stored as text
Line C — Pixel colours are stored as binary numbers, not text.
Question 4
A Images are made of pixels
B Each pixel has RGB values
C More pixels increase detail
D More pixels reduce resolution
Line D — More pixels actually increase resolution, not reduce it.
Question 5
A RGB never stores colour
B Pixels store colour data
C Binary stores each value
D More pixels mean higher res
Line A — RGB does store colour - each pixel's colour is RGB values.

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