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.
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!
Practice questions for Images & Sound
What does colour depth refer to in a digital image?
Explain the effect of increasing colour depth on a digital image. Refer to both file size and image quality in your answer.