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3.3 Data RepresentationIntroduction

The Digital Camera Trick

Part of Images & Sound · GCSE GCSE Computer Science revision

This introduction covers The Digital Camera Trick within Images & Sound for GCSE Computer Science. Revise Images & Sound in 3.3 Data Representation for GCSE Computer Science with 18 exam-style questions and 16 flashcards. This topic shows up very often in GCSE exams, so students should be able to explain it clearly, not just recognise the term. It is section 1 of 12 in this topic. Use this introduction to connect the idea to the wider topic before moving on to questions and flashcards.

Topic position

Section 1 of 12

Practice

18 questions

Recall

16 flashcards

The Digital Camera Trick

Your phone camera doesn't actually "take a picture" - it takes millions of tiny measurements! Each pixel (dot) gets 3 numbers: how much red (0-255), how much green (0-255), how much blue (0-255). A 12-megapixel photo = 12 million pixels × 3 colors × 1 byte = 36 MB! Similarly, recording sound means measuring air pressure thousands of times per second. CD quality = 44,100 measurements per second × 2 ears × 2 bytes = 176 KB/second. Digital media isn't magic - it's just lots and lots of numbers!

Keep building this topic

Read this section alongside the surrounding pages in Images & Sound. That gives you the full topic sequence instead of a single isolated revision point.

Image and Sound Data RepresentationDeep Dive: Digitizing the Analog WorldImage Representation - Bitmap Graphics

Practice Questions for Images & Sound

What does colour depth refer to in a digital image?

  • A. The number of pixels in the image
  • B. The number of bits used to represent each pixel's colour
  • C. The physical dimensions of the image in centimetres
  • D. The number of samples taken per second
1 markfoundation

Explain the effect of increasing colour depth on a digital image. Refer to both file size and image quality in your answer.

3 marksstandard

Quick Recall Flashcards

18 questions on Images & Sound — practise free

Instant marking, adaptive difficulty, and 16 spaced repetition flashcards. Free until your GCSEs.

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Image and Sound Data Representation