contours.py

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
# OpenCV required

import os
import sys
import numpy as np
import cv2
from global_functions import ensureDir


def main(path):
    src = cv2.imread(path)
    src = cv2.resize(src, (0, 0), fx=0.7, fy=0.7)
    gray = cv2.cvtColor(src, cv2.COLOR_BGR2GRAY)
    thresh = cv2.threshold(gray, 127, 255, 0)[1]

    _, contours, _ = cv2.findContours(
        thresh, cv2.RETR_TREE, cv2.CHAIN_APPROX_SIMPLE)
    contoursLen = len(contours)
    plantsNumber = 0
    colorStep = int(200.0 / contoursLen)
    PERIMETER_LIMIT = 30
    LINE_WIDTH = 2

    for i in range(contoursLen):
        perimeter = cv2.arcLength(contours[i], True)
        if perimeter > PERIMETER_LIMIT:
            plantsNumber += 1
            val = (i + 1) * colorStep
            cv2.drawContours(src, [contours[i]], -1,
                             (val, val, val), LINE_WIDTH)
            print("(" + str(val) + "," + str(val) + "," +
                  str(val) + ") : " + str(perimeter))

    print("\n" + str(plantsNumber) + " plants.")

    cv2.imshow("Contours", src)
    cv2.waitKey(0)
    cv2.destroyAllWindows()


def printUsage():
    print("""
    USAGE:
    python contours.py <img-path>
    e.g.: python contours.py bar/foo.jpg
    """)


if __name__ == "__main__":
    if len(sys.argv) > 1:
        src = sys.argv[1]
        main(src)
    else:
        printUsage()