Pywayne Cv Geometric Hull Calculator

Geometric hull calculator for 2D point sets supporting convex hull, concave hull (concave-hull, alphashape), and minimum bounding rectangle. Use when working...

Security Scan

The skill's instructions, requirements, and scope match its stated purpose (a Python-based geometric hull helper) and it does not request unrelated credentials, installs, or system access.

Purpose & Capability

Name, description, and SKILL.md all describe a 2D geometric-hull calculator using numpy, OpenCV, scipy, alphashape/concave_hull, and shapely — the requested libraries are appropriate for that functionality.

Instruction Scope

SKILL.md only shows Python usage examples and visualization calls; it does not instruct the agent to read arbitrary files, access environment variables, or send data to external endpoints. It remains within the stated purpose.

Install Mechanism

This is an instruction-only skill with no install spec and no code files, so nothing will be written to disk or downloaded by the skill itself.

Credentials

No environment variables, secrets, or config paths are requested; the listed Python packages are proportional to the described capabilities.

Persistence & Privilege

always is false and the skill is user-invocable. Autonomous invocation is allowed by default but is not combined here with any broad credential requests or persistent installation.

Assessment

This skill is internally consistent, but note that SKILL.md refers to a Python module (pywayne.cv.geometric_hull_calculator) that is not included here and the skill has no homepage or source listed. Before running: (1) verify you have the listed Python packages installed from trusted sources (numpy, OpenCV, scipy, alphashape/concave_hull, shapely, matplotlib); (2) confirm the pywayne module's provenance or inspect its code if you obtain it — importing unknown packages can run arbitrary code; (3) be aware visualization calls may open windows or require a GUI/backend; and (4) if you plan to supply sensitive data, remember the skill only handles point sets but always validate where data may be logged or transmitted by your runtime environment.

Pywayne Geometric Hull Calculator

This module computes geometric hulls (convex and concave) for 2D point sets.

Quick Start

from pywayne.cv.geometric_hull_calculator import GeometricHullCalculator
import numpy as np

# Create calculator with random points
points = GeometricHullCalculator.generate_random_points(num_points=50)
calculator = GeometricHullCalculator(points, algorithm='concave-hull')

# Get results
print(f"MBR: {calculator.get_mbr()}")
print(f"Convex Hull: {calculator.get_convex_hull()}")
print(f"Concave Hull: {calculator.get_concave_hull()}")

# Visualize with matplotlib
calculator.visualize_matplotlib()

Initialization

# algorithm options: 'concave-hull' or 'alphashape'
# use_filtered_pts: Enable point filtering based on radius
calculator = GeometricHullCalculator(
    points=your_points,
    algorithm='alphashape',
    use_filtered_pts=True
)

Supported Algorithms

Algorithm	Description
concave-hull	Concave hull using concave_hull library
alphashape	Concave hull using alphashape library

Hull Types

Type	Method	Description
Convex Hull	get_convex_hull()	Outer hull containing all points
Concave Hull	get_concave_hull()	Inner concave boundary

Properties

Property	Description
points	Input 2D points (N×2 numpy array)
algorithm	Algorithm used for concave hull
use_filtered_pts	Whether filtered points were used
box	Minimum Bounding Rectangle corners
center	Center point of input points
filter_radius	Radius used for point filtering
concave_hull_result	Concave hull points or polygons

Visualization

OpenCV Visualization

calculator.visualize_opencv()

Displays: All input points, MBR, center, filter circle (if enabled), concave hull (green), convex hull (red).

Matplotlib Visualization

calculator.visualize_matplotlib()

Displays: All input points (red), MBR (blue), center, filter radius circle (if enabled), concave hull (orange), convex hull (purple).

Requirements

• numpy - Array operations
• cv2 (OpenCV) - For OpenCV visualization and MBR computation
• matplotlib - For matplotlib visualization
• scipy - For convex hull computation
• concave_hull - Concave hull algorithm
• alphashape - Alphashape algorithm
• shapely - Polygon operations for area calculation

Notes

• Point filtering uses radius = 30% of shorter MBR edge length
• MBR computed using OpenCV's minAreaRect
• Convex hull uses scipy's ConvexHull
• Supports both single Polygon and MultiPolygon from alphashape results