Small holes and thin bridges disappear after tracing
Compare the source, binary preview, traced outline and imported geometry in order. The first stage that loses the feature tells you which correction to test.
A missing detail is usually lost before export: the source may not contain enough contrast or pixels, thresholding may close a gap, cleanup may remove a component, or the receiver may display the path differently. Check each stage with the same feature instead of changing every parameter at once.
Locate the first failed stage
Use one named feature, such as a 3 × 3 mm hole, a narrow bridge or a separate island. Mark where it appears in the original and compare that same feature after every processing stage.
The table separates source detail, binary classification, contour generation and receiver display. A closed file or successful download does not prove that every small feature survived.
| Stage | What changed | Evidence to inspect |
|---|---|---|
| Source image | The hole or bridge is faint, blurred or below the pixel resolution | Original pixels, contrast and feature width before tracing |
| Binary preview | Threshold closes a gap or turns a light part into background | Black/white preview at the selected threshold and inversion state |
| Traced outline | Cleanup or node reduction changes a surviving component | Contour count, hole count and outline before export |
| Imported file | The file contains the path but the receiver hides, fills or overlaps it | Selected geometry, fill/stroke, zoom and receiver version |
Check source, binary, contour and import
Name and measure the feature
Choose one hole, bridge or separate component and record its approximate source-pixel size. Keep the original file unchanged while diagnosing.
Inspect the source image
Zoom the original and check contrast, blur, compression, transparency and neighboring pixels. If the feature is not present here, tracing cannot recreate it.
Compare the binary preview
Use the threshold and inversion controls to see when the gap opens or the component appears. Change one parameter, recalculate, and record the result.
Check contours before simplifying
Count holes, bridges and independent components in the outline preview. Keep cleanup and node reduction off for the baseline; simplification can change a valid contour but cannot restore a missing one.
Reparse and inspect the import
Open the downloaded SVG or DXF, select the relevant paths and check fill, closure, overlap and zoom in the target editor. A parser pass proves syntax and geometry checks only, not every receiver display.
Use a fixture with known small features
The project fixture has transparent margins, a 50 × 40 mm opening, a 10 × 10 mm island, a 3 × 3 mm small hole and a lower-right notch. The PNG, SVG and DXF let you compare the input, traced paths and exported geometry.
Use the same feature at each stage and write down the threshold, cleanup, node reduction, output format and receiver version. This fixture is an engineering check for the project, not a promise that every small detail survives every tool or material process.
Match the correction to the failed stage
| Symptom | Next correction |
|---|---|
| Feature is absent in the original | Use a clearer or larger source; do not expect threshold or node settings to invent pixels. |
| Feature disappears in the binary preview | Adjust threshold or inversion one step at a time and compare the binary result; review transparency compositing separately. |
| Feature is in binary but absent from the outline | Turn off speck removal and node reduction, recalculate, and check contour limits before exporting. |
| Feature is in the file but not visible after import | Select the path and inspect fill, stroke, overlap, zoom and receiver settings; do not rewrite the source before locating the display cause. |
Continue with related checks
Use the PNG/SVG tools for a fresh binary and outline comparison, the node guide for a measured simplification decision, and the logo guide when the source is a mark with thin bridges or holes.
Sources and verification
The stage sequence follows the project’s browser processing model: decode and threshold the pixels, trace contours, validate the export, then inspect the receiving editor. The linked methodology documents the scope and limits of those checks.