Computer vision
A picture is just numbers
🎓 School maths · Years 5–6Coordinates & grids — Read a value at a position on a 2-D grid of numbers.Maths by year →
The Case. Your phone sees photos as numbers, not pictures. Can you see the picture hiding inside a grid of numbers?
Your tools. numpy holds the grid; matplotlib paints each number as a bright or dark pixel.
Investigate. Press Run. Every number becomes a pixel — bigger numbers are brighter. A shape appears!
- Change some 9s to 0s and re-run — you're editing the photo pixel by pixel.
- This is how every photo works: a big grid of brightness numbers.
your_code.py
Starting Python…
The Reveal
Starting Python… (first time only — a few seconds)
🗒️ Detective's notes
Bundles your findings, chart and code into one PDF you can keep, print or hand in.
🧩 How this code works
The tools it uses
- NumPy — a row of boxes that holds numbers, so you can do maths to all of them at once.
- Matplotlib — your crayon box — it turns numbers into charts and pictures.
What this one does
- • It shows an image made of numbers.
- • It finds the biggest value.
How to read it, top to bottom
- 1. Import — bring in the tools (listed above).
- 2. The data — the lists and numbers near the top. These are the bits you change.
- 3. The work — a little maths, or a loop that repeats a step.
- 4. Show it —
print(...)writes words;plt.show()draws the picture.
Use it for your own problems
- Change the numbers at the top and press Run — nothing breaks, so experiment!
- Ask your own version of the question — swap in your family, your scores, your week.
- The same tools work on any numbers — that's the superpower you're learning.
Need a hint?
Try setting a whole row to 9s — that row lights up white. The computer only ever sees these numbers.