What actually changes.
If transparency is simply composited against white while reading the file, white artwork disappears completely. Vector Boy respects the alpha channel and treats visible pixels separately from the transparent background.
For semi-transparent edges, opacity and visible colour work together during detection. That matters for antialiased logos and lettering. Result view shows which regions will become part of the final shape.
What the PNG contains
- PNG 8 can store transparency through its palette or a transparent index
- PNG 24 or PNG 32 commonly uses a separate alpha channel
- White artwork remains visible when its alpha value is above zero
- Semi-transparent edges need a deliberate threshold setting
Step by step.
- Load the PNG directly without adding a coloured background.
- Compare Original and Result, especially for white artwork.
- Set Black level so semi-transparent edges are included sensibly.
- Inspect Result view for unintended fringe pixels.
- Check contours and counters in Vector view.
- Export a vector format with a transparent background.
RGB values hidden inside fully transparent pixels do not belong to the visible motif. Visible colour and opacity matter, not colour data underneath alpha zero.
Questions before export.
Can Vector Boy detect white artwork on transparency?
Yes. Visible white pixels are identified through alpha even though they would disappear on a white surface.
Does the SVG background stay transparent?
Yes. The vector export contains the shape without an additional white background object.
What happens to soft shadows?
Depending on opacity and threshold they become partly or not at all part of the black shape. That is normally desirable for clean vectors.