MorphoTrace 0.4.0

First release.

Annotation

• Outline by clicks or freehand (Shift + drag); close on the first vertex, with Enter or a double-click.
• Draw, Subtract and Edit modes: overlapping outlines merge, subtracted areas and holes are cut out, vertices can be moved, added and deleted; undo/redo per image.
• Zoom at the cursor, pan, display-only brightness, contrast and invert (also in Safari).
• Per-image unusable flag with a reason; annotator ID, scale (µm/px) and time per image recorded.

Measurement

• area_px_polygon: exact area of the region the outlines cover (overlaps once, holes subtracted, self-intersecting outlines resolved).
• area_px_mask: pixel count of the exported mask, rasterised by pixel centre from the same region.
• Areas in mm² from the scale; areas per part label.

Data

• Export CSV, JSON (all vertices; re-importable) and a ZIP of PNG masks; image sizes are reported also for images not opened.
• Autosave in the browser, with a persistent warning and an export button if it fails.

Quality

• Keyboard access, screen-reader announcements and colour-independent cues (axe-core WCAG 2.1 AA).
• Tested automatically in Chromium, Firefox and WebKit (tests/run-all.sh, GitHub Actions).