Starter quiz
- What is a binary digit (bit)?
- A group of 8 bits
- A method of character representation
- The basic unit of data within a computer system that has the value 0 or 1 ✓
- A sequence of symbols
-
- What is a group of 8 bits called?
- 'byte' ✓
- What does a character set do?
- Matches characters to a unique binary sequence ✓
- Represents images in bitmap format
- Uses up to 32 bits per character
- Measures file size
-
- Which character representation method uses 8 bits per character?
- 'ASCII' ✓
- What is the method of character representation that uses up to 32 bits per character?
- 'Unicode' ✓
- How many possible states are there in a sequence of 3 bits?
- 4
- 6
- 8 ✓
- 16
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Exit quiz
- Which term refers to an image format that is composed of a grid of individual pixels, each with its own colour value?
- Resolution
- Colour Depth
- Bitmap ✓
- Pixel
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- What determines the quality of a bitmap image?
- Its size on the screen
- Its resolution ✓
- The number of colours it uses
- The type of computer used
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- What is the smallest element of a bitmap image?
- 'pixel' ✓
- Why might a bitmap image look pixelated?
- Low resolution ✓
- High colour depth
- Large file size
- Small screen size
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- Which term describes the number of bits used to represent the colour of each pixel in an image?
- Resolution
- Pixel
- Bitmap
- Colour depth ✓
-
- Match the term to its definition:
- 8-bit colour depth⇔Allows for 256 different colours. ✓
- 16-bit colour depth⇔Allows for 65,536 different colours. ✓
- 24-bit colour depth⇔Allows for 16.7 million different colours. ✓
Worksheet
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Lesson Details
Key learning points
- A pixel is the smallest element in an image.
- A bitmap image is one that is represented by a grid of pixels.
- The colour a pixel should display is described by a binary sequence.
- The colour depth of a bitmap image quantifies the number of bits used to represent each pixel.
- The resolution of an image describes the total pixels an image contains based on its width and height.
Common misconception
Bitmap images that are large on screen are always poor quality.
The quality of a bitmap image depends on its resolution, not just its size on the screen. A high-resolution bitmap can appear sharp and detailed, while a low-resolution bitmap may look pixelated when enlarged.
Keywords
Pixel - the smallest element of an image
Colour depth - the number of bits used to represent the colour of each pixel
Resolution - total amount of pixels an image contains based on its width and height expressed in pixels
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