trace-skeleton 0.1.6

Trace and label skeleton of a 2D image.

The trace_skeleton Python package

A python package for tracing the skeleton of a 2D image. This work uses the Skeleton Tracing algorithm developed by LingDong. This repo provides an easy to install python package for tracing the skeleton. This is done to ease the use of the algorithm in other Python projects. We've taken the SWIG C implementation for optimal performance.

Usage

Quick and easy installation:

pip install trace-skeleton

Example

The examples shown are a copy-paste from the original repo.

import trace_skeleton
import cv2
import random

im = cv2.imread("../test_images/opencv-thinning-src-img.png",0)

_,im = cv2.threshold(im,128,255,cv2.THRESH_BINARY);

polys = trace_skeleton.from_numpy(im);

for l in polys:
	c = (200*random.random(),200*random.random(),200*random.random())
	for i in range(0,len(l)-1):
		cv2.line(im,(l[i][0],l[i][1]),(l[i+1][0],l[i+1][1]),c)

cv2.imshow('',im);cv2.waitKey(0)

Advanced

The aforementioned API's have a tiny linear time overhead for transforming input and output between internal datastructures and python objects. Alternatively, you can use the following:

from trace_skeleton import *

im = "\0\1\0\0\1\0\0\1\0 ..... " #image stored as a (char*)
w = 128 #dimensions
h = 64

trace(im,w,h)

# iterate over each point in each polyline
# by popping them off the internal datastructure
# len_polyline() gets the length of current polyline
# -1 means no more polylines
while (len_polyline() != -1):
	n = len_polyline();
	for i in range(0,n):
		# pop_point() retrieve and remove the next point
		# on the polyline. It returns the flat index in image
		# mod/div it with width to get (x,y) coordinate
		idx = pop_point()
		x = idx % w;
		y = idx //w;
		print(x,y)
	print("\n")