Serialising Shapely objects to JSON

Lately I’ve been using Shapely to perform geometry operations, and I’ve come across the need to serialise a number of objects in a Python data structure to JSON. I’ve chosen to use a custom JSONEncoder and JSONDecoder class.

import json from shapely.geometry.base import BaseGeometry from shapely.geometry import shape, mapping class ShapelyEncoder(json.JSONEncoder): def default(self, obj): if isinstance(obj, BaseGeometry): return mapping(obj) return json.JSONEncoder.default(self, obj) class ShapelyDecoder(json.JSONDecoder): def decode(self, json_string): def shapely_object_hook(obj): if 'coordinates' in obj and 'type' in obj: return shape(obj) return obj return json.loads(json_string, object_hook=shapely_object_hook) def export_to_JSON(data): return json.dumps(data, indent=4, sort_keys=True, cls=ShapelyEncoder) def load_from_JSON(json_string): return json.loads(json_string, cls=ShapelyDecoder)

OpenCV – Mown grass detection in video

Following on from OpenCV – Mown grass detection. I recorded a video on my phone, and am attempting to determine the line between grass and footpath, to aid a grass mowing robot. Continue reading →

Final Year Engineering Project

My thesis project was entitled “Towards Real-Time 3D Meshless Computations on GPU for Surgery Simulation”, which is an obtuse way of saying “a way to improve the speed and accuracy of brain surgery simulation by using GPUs”. Continue reading →

OpenCV – Mown grass detection

Over lunch today, a few friends and I were discussing the possibility of an autonomous grass mowing robot. We decided that the major problem was navigation – following the edge of the lawn that has been previously mown. I present a (relatively) simple method using Python and OpenCV to estimate the border between areas of cut and uncut grass. Continue reading →

Sonicwall Pro 2040 Teardown

A quick look inside a Sonicwall Pro 2040 firewall and VPN device. Continue reading →