scan.py

# -*- coding: utf-8 -*-
"""
Created on Wed Jul 10 23:04:32 2019

@author: Manoj Sree Harsha
"""
from transform import four_point_transform
from skimage.filters import threshold_local
import cv2
import imutils

image = cv2.imread("doc.jpg")
ratio = image.shape[0]/500.0
orig = image.copy()
image = imutils.resize(image, height=500)
gray = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)
gray = cv2.GaussianBlur(gray, (5, 5), 0)
edged = cv2.Canny(gray, 75, 200)
cnts = cv2.findContours(edged.copy(), cv2.RETR_LIST, cv2.CHAIN_APPROX_SIMPLE)
cnts = imutils.grab_contours(cnts)
#sorting contours by area and finding the max one.
cnts = sorted(cnts, key = cv2.contourArea, reverse = True)[:5]
 # loop over the contours
for c in cnts:
	# approximate the contour
	peri = cv2.arcLength(c, True)
	approx = cv2.approxPolyDP(c, 0.02 * peri, True)
 
	# if our approximated contour has four points, then we
	# can assume that we have found our screen
	if len(approx) == 4:
		screenCnt = approx
		break
cv2.drawContours(image, [screenCnt], -1, (0, 255, 0), 2)
warped = four_point_transform(orig, screenCnt.reshape(4, 2) * ratio)
warped = cv2.cvtColor(warped, cv2.COLOR_BGR2GRAY)
T = threshold_local(warped, 11, offset = 10, method = "gaussian")
warped = (warped > T).astype("uint8") * 255
cv2.imshow("Original", imutils.resize(orig, height = 650))
cv2.imshow("Scanned", imutils.resize(warped, height = 650))
cv2.waitKey(0)