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Selected work / 02 · Geospatial engineering

From map imagery
to usable geometry.

Scottish Title-Shape Extraction Pipeline: combining computer vision, spatial processing and validation for a high-volume title dataset.

11,000+Records in the pipeline scope
EPSG:27700Spatial processing reference
PostGISSpatial data platform
Workflow illustration. No source records or internal system screens are shown.

The context

Finding the shape
inside the image.

The work involved extracting Scottish title shapes from WMS imagery and preparing them for spatial data workflows. Image-derived shapes needed checks before they could become database records.

At Nimbus Property Systems, I automated a title-shape pipeline for 11,000+ records using Python, OpenCV, PostGIS, WMS imagery and EPSG:27700 processing.

The workflow

Image processing meets spatial SQL.

  1. Use WMS imagery

    Work with the imagery associated with Scottish title records.

  2. Extract candidate title shapes

    Apply Python and OpenCV image processing, including colour and contour rules.

  3. Process spatial geometry

    Use EPSG:27700 processing and PostGIS as part of the geospatial workflow.

  4. Validate before insertion

    Apply area, topology, duplicate and failure-validation checks before database insertion.

Illustrative pipeline. It does not display a real title image or extracted boundary.

Validation

Not every contour
is a usable record.

The pipeline applied multiple rules before database insertion, rather than treating every detected shape as a valid result.

Area & topologyChecks on shape area and geometric validity.
Colour & contoursRules for the image-derived shape candidates.
Duplicate recordsDuplicate-handling checks before insertion.
Failed extractionsFailure-validation rules and troubleshooting.

My contribution

Automation with
quality controls.

  • Automated the high-volume Scottish title-shape workflow using Python, OpenCV, PostGIS and WMS imagery.
  • Applied EPSG:27700 processing and area, topology, colour, contour, duplicate and failure-validation rules before insertion.
  • Diagnosed failed image extraction and geometry issues, using processing logs and QA tables to refine rules and improve reliability.

The delivery

A controlled path from image to record.

The resulting workflow joined image processing with spatial validation and database insertion. Its scope covered 11,000+ records, with checks designed to identify unsuitable or failed extractions.

Finding a boundary is one step. Making it a trustworthy spatial record is the engineering work.

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