radupotop / hackathon-ps

Polestar Hackathon 2019

Flood fill

1. Find a seed point (the original port coordinates).
   • Will be semi-automated.
2. Do a quantitize and fill on the map to detect land edges.
   • This detects the outline of Points Of Interest such as terminals and berths.
3. Put bounding boxes around those POIs and built Rtrees indices in PostGIS
   • Determine bounding boxes
   • Create PostGIS polygons from them

Quantitize process

• Process image: quantitize and fill, compute histogram, redo if the image has been filled poorly, e.g. has too much red.
• Don't go past 9 colour levels for quantitization.
• Apply additional filters if necessary.

Potrace

potrace felixstowe.bmp -b geojson

From the SeedPoint determine the origin of the map (x0, y0 coordinates).

Example CLI calls

http --timeout 120 http://localhost:5000/ seedpoint==0,0 @images/southampton.png -d -o output/southampton.png

http --timeout 120 http://localhost:5000/ seedpoint==1000,700 @images/felixstowe.png -d -o output/felixstowe.png