1.2 · Lesson 3 of 3
Images
Syllabus 1.2.3
What this lesson covers
- Explain how and why images are stored, including the effect of resolution and colour depth
Key vocabulary
- Bitmap
- An image made up of a grid of pixels, each stored as a binary value.
- Pixel
- The smallest identifiable part of an image. It can only be one colour.
- Colour depth
- The number of bits used to represent the colour of each pixel.
- Resolution
- The number of pixels in an image, e.g. 1920 × 1080.
- File size
- Width × height × colour depth gives the size of an image in bits.
Check your learning
- Quick check: 4 questions
- Key vocabulary test: 5 terms
- Activity 1: Paint the bitmap · 4 questions
- Activity 2: Colour depth and file size · 8 questions
- Activity 3: Smallest to largest file · drag and drop