ECG Annotator MVP

React + TypeScript ECG annotation MVP.

Run

npm install
npm run dev

Features (MVP)

• Upload ECG image (png/jpg/webp) or PDF (renders page 1)
• Toolbar: select, vertical line, horizontal line, caliper, circle, rectangle, arrow
• Color + stroke width controls
• Drag annotations in Select mode
• Undo/Redo (20 steps)
• Export annotations JSON
• Export PNG snapshot

Shortcuts

• Delete: remove last annotation
• Ctrl/Cmd + Z: undo
• Ctrl/Cmd + Shift + Z: redo
• Esc: back to Select tool

Known limitations

• PDF supports first page only
• Zoom/pan + transform handles are not fully implemented yet
• Delete currently removes last annotation (selection delete pending)
• Caliper distance label is pending

Structure

• src/App.tsx
• src/components/Toolbar.tsx
• src/components/StageCanvas.tsx
• src/hooks/useHistory.ts
• src/utils/pdfToImage.ts