Module 02 Knowledge Check
5 questions. Pass mark 4 out of 5. Answer every question before checking the answer key below, then retry after reading the feedback.
1. Image format should be determined from…
- A. the file extension
- B. the file's header bytes
- C. the directory it is in
- D. the file size
2. Resizing an image down and back up…
- A. recovers the original
- B. permanently destroys fine detail
- C. only affects colour
- D. is lossless with the right interpolation
3. HSV is most useful when you need to…
- A. reduce memory
- B. pick a colour independent of brightness
- C. speed up convolution
- D. compress the image
4. A model trained on quality-95 JPEGs and served quality-40 ones…
- A. performs identically
- B. sees a systematically different distribution
- C. raises a decoding error
- D. is unaffected because JPEG is lossless
5. A loader that silently skips undecodable files…
- A. is good practice
- B. hides both dataset shrinkage and upstream changes
- C. is required for robustness
- D. improves training speed
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Answer Key and Explanations
Check these only after attempting every question.
1. B - the file's header bytes
An extension is a claim. Trusting it produces a decoder error deep in a training loop on one unnamed file.
2. B - permanently destroys fine detail
Anything a few pixels across in the original is gone before the model sees it, whatever the architecture.
3. B - pick a colour independent of brightness
'Find the yellow object' is a hue range in HSV and an awkward condition in BGR that breaks when lighting changes.
4. B - sees a systematically different distribution
JPEG error is structured, following the 8x8 block grid, not random noise.
5. B - hides both dataset shrinkage and upstream changes
Return the reason and count rejections by kind - a rise in one kind is a signal about a source.
Practical Check
Apply this module to your own work: complete the module activity for *Loading, Resizing, Colour Spaces and File Formats*, then write one sentence naming what your result shows and one naming what it does not.
Strong Answer Pattern
A strong answer names the task, the evidence used, the check performed, and the remaining limitation. It avoids "proved", "guaranteed", or "always" unless the evidence genuinely supports it.