Question Constellation Sign up for free AQA · GCSE · Computer Science · Higher
Colour-depth effect on file size
The number of colours used in Image C and Image D in Figure 2 are both increased by one.
State the impact of this increase on the minimum file sizes of both Image C and Image D.
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Marking points
- 1 States that Image C's minimum file size increases.
- 2 States that Image D's minimum file size stays the same.
Full-mark answer
Image C: the minimum file size would increase (it would double). Image D: the minimum file size would stay the same.
Why this answer loses marks
Both file sizes increase because both images use one more colour.
Check the minimum bit depth separately for each image; an extra colour does not always cross a bit-depth boundary.