What actually changes.
A clean source needs very little work from Black level, Contrast and Brightness. I only check whether black is truly black and white is genuinely background. Then I compare Fine and Subpixel for curves and diagonal edges.
Pixel preserves every raster step. Fine samples the contour more densely. Subpixel estimates the transition between pixel centres. The right mode depends on whether the raster edge is part of the design or something you want to remove.
A useful black and white source
- Black is opaque rather than dark grey
- The background is evenly white or transparent
- Small counters remain clearly separated
- Resolution shows the finest important stroke
Step by step.
- Load the source and compare Result with Original.
- Change tonal controls only when grey halos or gaps are visible.
- Select Fine first in Vector view.
- Test Subpixel as well for small curves.
- Add smoothing and simplification sparingly.
- Inspect closed paths and counters before export.
A small black and white file remains a small source of information. The vector becomes scalable, but it cannot know a curve that was represented by only a handful of pixels.
Questions before export.
Why recalculate an image that is already black?
Pixels still need to be translated into contours and genuine paths. That is more than changing a file extension.
Should I use Fine or Subpixel?
Fine is a good default. Subpixel can calm curves and diagonal lines further on clean sources.
Does white remain in the export?
White is treated as a cut-out. The export does not contain an additional white background object.