''' file name : findcontours.py

Description : This sample shows how to find and draw contours

This is Python version of this tutorial : http://opencv.itseez.com/doc/tutorials/imgproc/shapedescriptors/find_contours/find_contours.html#find-contours

Level : Beginner

Benefits : Learn to use 1) cv2.findContours() and 2)cv2.drawContours()

Usage : python findcontours.py

Written by : Abid K. (abidrahman2@gmail.com) , Visit opencvpython.blogspot.com for more tutorials'''

import cv2
import numpy as np

def thresh_callback(thresh):
    edges = cv2.Canny(blur,thresh,thresh*2)
    drawing = np.zeros(img.shape,np.uint8) # Image to draw the contours
    contours,hierarchy = cv2.findContours(edges,cv2.RETR_TREE,cv2.CHAIN_APPROX_SIMPLE)
    for cnt in contours:
	if len(cnt) < 50:
	        color = np.random.randint(250,255,(3)).tolist() # Select a random color
        	cv2.drawContours(drawing,[cnt],0,color,1)
	        cv2.imshow('output',drawing)
		M = cv2.moments(cnt)
		perimeter = cv2.arcLength(cnt,True)
		print M
		print perimeter
		hull = cv2.convexHull(cnt)
        	cv2.drawContours(drawing,[hull],0,(255,0,0),1)
		rect = cv2.minAreaRect(cnt)
		box = cv2.cv.BoxPoints(rect)
		box = np.int0(box)
		cv2.drawContours(drawing,[box],0,(0,0,255),2)
#		(x,y),radius = cv2.minEnclosingCircle(cnt)
#		center = (int(x),int(y))
#		radius = int(radius)
#		cv2.circle(img,center,radius,(0,255,0),2)
    cv2.imshow('input',img)

img = cv2.imread('test.jpg')
gray = cv2.cvtColor(img,cv2.COLOR_BGR2GRAY)
blur = cv2.GaussianBlur(gray,(5,5),0)

cv2.namedWindow('input',cv2.WINDOW_AUTOSIZE)

thresh = 100
max_thresh = 255

cv2.createTrackbar('canny thresh:','input',thresh,max_thresh,thresh_callback)

thresh_callback(thresh)

if cv2.waitKey(0) == 27:
    cv2.destroyAllWindows()