Images
Should sampling and reconstruction be a separate chapter? It’s intimately tied to images.
Prefilters for Sharp Image Display is a fantastic resource for sampling and reconstruction. Rocha’s masters thesis, Optimal prefilters for display enhancement, covers the same material and provides even more background. Some points we definitely want to cover:
- Tradeoff between aliasing, ringing, and sharpness
- Pure sinc filter is wrong; prioritizes aliasing and sharpness, ringing is bad
- Box filter is good for sharpness but bad on aliasing
- Oblique projections
- First filter determines aliasing vs ringing tradeoff
- Second filter improves sharpness
- Clamping
- Serious issue for text, less so natural images
- HDR may reduce need for clamping positive light
A Fresh Look at Generalized Sampling is a deep theoretical exploration into filtering and reconstruction.