🗺️ Map Alignment / Warp Tool

Align an overlay image (any projection / crop) onto a fixed base map using control-point warping (Thin Plate Spline), then export the flattened result as JPEG or PNG.

How it works

  1. Upload your Base Map (the fixed reference) and your Overlay Image (the one to align).
  2. Click a landmark on the Base Map (left), then click the same landmark on the Overlay (right). That's one point pair. Add 5–10 spread across the map for best results.
  3. Zoom: scroll wheel / pinch gesture / +/− buttons — zooms toward your cursor or pinch center. Works on Base, Overlay, and the Result Preview.
  4. Pan: click-and-drag on empty space.
  5. Move a pin: click-and-drag starting directly on the pin.
  6. Delete a pin: double-click / double-tap it — this also removes its paired point on the other side.
  7. The preview updates automatically. Adjust opacity to compare, then download the flattened image.

Step 1: Upload a base map image.

Upload a base map image to begin. You can also drag & drop image files onto the boxes below.

Base Map (fixed reference)

100%

Click empty space = place point & pan. Drag a pin = move it. Double-click a pin = delete pair. Scroll / pinch to zoom. You can also drag & drop an image file onto this box to load or replace the base map.

Overlay Image (to be warped)

100%

Click matching spot to pair. Drag a pin = move it. Double-click a pin = delete pair. Scroll / pinch to zoom. You can also drag & drop an image file onto this box to load or replace the overlay.

Overlay opacity 85%

Result Preview (this is what gets exported)

100%

Scroll / pinch to zoom, drag to pan — this is just for checking alignment closely; it does not affect the exported resolution.