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contours and hirerachy mismatch

C:\fakepath\original.jpg(/upfiles/1542707582239963.jpg)(/upfiles/15427075603671739.jpg)

Hi When I use the below code without bothering hirerachy , it is able to detect external contours correctly . Pl see the attached file “drawn-NO-hirerachy”. My original image has three external contours . cnts = cv2.findContours(edged.copy(), cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)

when I use hirerachy code , it is not detecting external contours correctly . It shows a few points that I red circled in “drawa-with hirerachy”

im,cnts,hierarchy = cv2.findContours(edged.copy(), cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)

Following is the code I am using

import the necessary packages

import numpy as np import cv2 import imutils import pytesseract from PIL import Image, ImageEnhance from imutils.perspective import four_point_transform from array import *

load the example image

image = cv2.imread("h2.jpg")

pre-process the image by resizing it, converting it to

graycale, blurring it, and computing an edge map

image = imutils.resize(image, height=500) gray = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY) blurred = cv2.GaussianBlur(gray, (5, 5), 0) edged = cv2.Canny(blurred, 50, 200, 255)

cnts = cv2.findContours(edged.copy(), cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)

im,cnts,hierarchy = cv2.findContours(edged, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)

cnts = cnts[0] if imutils.is_cv2() else cnts[1]

cnts = sorted(cnts, key=cv2.contourArea, reverse=True)

print 'No Of Contours = ', len(cnts)

print 'No Of elements in hirerachy = ', len(hierarchy[0]) print hierarchy

major = cv2.__version__.split('.')[0]

print major

for c in cnts: cv2.drawContours(image, [c], -1, (0,255,0), 2)

cv2.imshow('EDGED',edged) cv2.imshow('DRAWN CONTOURS',image) cv2.imshow('RETURNED IMAGE',im) cv2.waitKey(0)

contours and hirerachy mismatch

~~C:\fakepath\original.jpg(/upfiles/1542707582239963.jpg)(/upfiles/15427075603671739.jpg)~~ $C:\fakepath\original.jpg$

cnts = cv2.findContours(edged.copy(), cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)cv2.CHAIN_APPROX_SIMPLE)

when I use hirerachy code , it is not detecting external contours correctly . It shows a few points that I red circled in “drawa-with hirerachy”

im,cnts,hierarchy = cv2.findContours(edged.copy(), cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)cv2.CHAIN_APPROX_SIMPLE)

Following is the code I am using
# import the necessary packages
packages import numpy as np import cv2 import imutils import pytesseract from PIL import Image, ImageEnhance from imutils.perspective import four_point_transform from array import * * # load the example image image = cv2.imread("h2.jpg") image image = cv2.imread("h2.jpg") # pre-process the image by resizing it, converting it to to # graycale, blurring it, and computing an edge map map image = imutils.resize(image, height=500) gray = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY) blurred = cv2.GaussianBlur(gray, (5, 5), 0) edged = cv2.Canny(blurred, 50, 200, 255) cnts 255) #cnts = cv2.findContours(edged.copy(), cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE) cv2.CHAIN_APPROX_SIMPLE) im,cnts,hierarchy = cv2.findContours(edged, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE) cv2.CHAIN_APPROX_SIMPLE) cnts = cnts[0] if imutils.is_cv2() else cnts[1] cnts[1] cnts = sorted(cnts, key=cv2.contourArea, reverse=True) reverse=True) print 'No Of Contours = ', len(cnts) len(cnts) print 'No Of elements in hirerachy = ', len(hierarchy[0]) print hierarchy hierarchy major = cv2.__version__.split('.')[0] print major cv2.__version__.split('.')[0] print major for c in cnts: cv2.drawContours(image, [c], -1, (0,255,0), 2) 2) cv2.imshow('EDGED',edged) cv2.imshow('DRAWN CONTOURS',image) cv2.imshow('RETURNED IMAGE',im) cv2.waitKey(0)cv2.waitKey(0)