QuadrilateralFitter

1.12 verified Fri May 01 auth: no python

QuadrilateralFitter is an efficient and easy-to-use Python library for fitting irregular quadrilaterals from irregular polygons or any noisy data. Current version is 1.12, released on PyPI. The library is actively maintained and provides a simple API to fit quadrilaterals to polygon data, often used in computer vision and geometry processing. Release cadence is irregular, with minor updates.

pip install quadrilateral-fitter

Common errors

error ImportError: cannot import name 'QuadrilateralFitter' from 'quadrilateral_fitter' ↓

cause Trying to import from the wrong module path or the package not installed correctly.

fix

Run 'pip install quadrilateral-fitter' and use 'from quadrilateral_fitter import QuadrilateralFitter'.

error TypeError: __init__() missing 1 required positional argument: 'polygon' ↓

cause QuadrilateralFitter requires the polygon argument at initialization.

fix

Provide the polygon as a list of coordinates: QuadrilateralFitter([(x1,y1), (x2,y2), ...])

Warnings

gotcha Input polygon must be a list of (x, y) tuples or a numpy array with shape (N, 2). Order matters: vertices should be in sequential order around the polygon. ↓

fix Ensure polygon is closed? Not required but points should be in order. For unordered points, the fit may produce unexpected results.

deprecated In version 1.x, the method 'fit' returns a 'Quadrilateral' object. In future versions, the API might change. Use the current pattern. ↓

fix Check documentation for any changes when upgrading.

Imports

QuadrilateralFitter
wrong
```
from quadrilateral_fitter import QuadrilateralFitter
```
correct
```
from quadrilateral_fitter import QuadrilateralFitter
```
The correct import uses underscore (quadrilateral_fitter) matching the package name.

Quickstart

Basic usage: fit a quadrilateral to a noisy polygon.

from quadrilateral_fitter import QuadrilateralFitter

# Example polygon: coordinates (x, y) list of points
polygon = [(0, 0), (1, 0), (1, 1), (0.5, 1.5), (0, 1)]

# Create fitter instance
fitter = QuadrilateralFitter(polygon)

# Fit the quadrilateral
fitted_quad = fitter.fit()

# Access fitted vertices
print(fitted_quad.vertices)