Section 3 · What Digital Images Are Made Of

Resampling

Definition

Changing the pixel count of a raster image, either by discarding pixels (downsampling) or generating new ones through interpolation (upsampling).

Why it matters

Upsampling invents detail that was never captured; it can rescue a slightly undersized image but cannot manufacture sharpness that doesn’t exist. Sourcing at adequate size beats resampling every time.

Example

Note

Worth knowing before you gather source imagery, not after. The fix for an inadequate source is a different source, and that’s only cheap early.