#!/usr/bin/env python

import numpy as np
import cv2
import sys

try:
    image_loc = sys.argv[1]
    im = cv2.imread(image_loc)
    hsv_img = cv2.cvtColor(im, cv2.COLOR_BGR2HSV)
except:
    if len(sys.argv) == 1:
        print "no image file included.\nusage: python contour.py image.png"
    else:
        print "no image located at %s " % image_loc
    sys.exit(1)
COLOR_MIN = np.array([0, 80, 80],np.uint8)
COLOR_MAX = np.array([22, 255, 255],np.uint8)
frame_threshed = cv2.inRange(hsv_img, COLOR_MIN, COLOR_MAX)
imgray = frame_threshed
ret,thresh = cv2.threshold(frame_threshed,22,255,0)
contours, hierarchy = cv2.findContours(\
        thresh,cv2.RETR_TREE,cv2.CHAIN_APPROX_SIMPLE)

# Find the index of the largest contour
areas = [cv2.contourArea(c) for c in contours]
max_index = np.argmax(areas)
cnt = contours[max_index]

# plot box around contour
x,y,w,h = cv2.boundingRect(cnt)
cv2.rectangle(im,(x,y),(x+w,y+h),(0,255,0),2)
cv2.imshow("Show",im)
cv2.waitKey(0)
cv2.destroyAllWindows()