CVTLowpoly: Image Lowpoly via Centroid Voronoi Diagram

Image Sharp Feature Extraction using Guide Filter's Local Linear Theory via opencv-python.

The Following two parts are bollowed from https://github.com/songshibo/JumpFlooding-taichi

2D/3D Voronoi tessellation using Jump Flooding algorithm(JFA). Adopt 1+JFA strategy to reduce errors.

2D Centroidal Voronoi Tessellation using Lloyd algorithm.

Installation

The Python package can be installed with Pypi:

pip install CVTLowpoly

Usage

import cv2, CVTLowpoly
img = cv2.imread(filename, cv2.IMREAD_ANYCOLOR)

# case1: get triangle mesh
V, F, _sharp_image = CVTLowpoly.lowpoly_mesh(img)

# case2: get lowpoly image and triangle mesh
lowpoly_img, V, F, FColor = CVTLowpoly.lowpoly_image(img)

Results

• Case 1: Source Image: 550x825(pixels: 453750), 1% sites

Source Image	CVTLowpoly(iters: 5, time: 1.7108s on Mac17-i5)

• Case 2: Source Image: 550x828(pixels: 455400), 1% sites

Source Image	CVTLowpoly(iters: 5, time: 2.0708s on Mac17-i5)

• Case 3: Source Image: 550x825(pixels: 453750), 1% sites

Source Image	CVTLowpoly(iters: 5, time: 0.7505s on Mac17-i5)

• Case 4: Source Image: 1193x834(pixels: 994962), 1% sites

Source Image	CVTLowpoly(iters: 5, time: 2.889s on Mac17-i5)

• Case 5: Source Image: 1193x834(pixels: 691200), 1% sites

Source Image	CVTLowpoly(iterations: 5, time: 2.763s on MacPro2017 i5)

Reference

Jump flooding in GPU with applications to Voronoi diagram and distance transform

GPU-Assisted Computation of Centroidal Voronoi Tessellation

Variants of Jump Flooding Algorithm for Computing Discrete Voronoi Diagrams

JumpFlooding-taichi

Semi-Isotropic Triangular Image Lowpoly