Document Scanner.py

# Imutils package tutorials : https://www.pyimagesearch.com/2015/02/02/just-open-sourced-personal-imutils-package-series-opencv-convenience-functions/
# import the necessary packages
from four_point_transform import four_point_transform
from skimage.filters import threshold_local
import argparse
import cv2
import imutils
import os

# # ################################### (Comment all lines to make an executable )
# # construct the argument parser and parse the arguments
# # ###################################
# ap = argparse.ArgumentParser()
# ap.add_argument("-i", "--image", required=True,
#                 help="Path to the image to be scanned")
# args = vars(ap.parse_args())
# # load the image and compute the ratio of the old height
# # to the new height, clone it, and resize it
# image = cv2.imread(args["image"])

CURRENT_DIR = os.path.dirname(os.path.abspath(__file__))
IMAGES_FOLDER_PATH = os.path.join(CURRENT_DIR, "Images")
IMAGE_FILE = os.path.join(IMAGES_FOLDER_PATH, "transform.jpg")
image = cv2.imread(IMAGE_FILE)

ratio = image.shape[0] / 500.0
orig = image.copy()
image = imutils.resize(image, height=500)
cv2.imshow("RESIZED", image)

# convert the image to grayscale, blur it, and find edges
# in the image
gray = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)
gray = cv2.GaussianBlur(gray, (5, 5), 0)
edged = cv2.Canny(gray, 75, 200)

# show the original image and the edge detected image
print("STEP 1: Edge Detection")
cv2.imshow("Image", image)
cv2.imshow("Edged", edged)
cv2.waitKey(0)
cv2.destroyAllWindows()
# find the contours in the edged image, keeping only the
# largest ones, and initialize the screen contour
contours = cv2.findContours(edged.copy(), cv2.RETR_LIST, cv2.CHAIN_APPROX_SIMPLE)
contours = contours[0] if imutils.is_cv2() else contours[1]
contours = sorted(contours, key=cv2.contourArea, reverse=True)[:5]

# loop over the contours
for c in contours:
    # 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:
        screen_contour = approx
        break

# show the contour (outline) of the piece of paper
print("STEP 2: Find contours of paper")
cv2.drawContours(image, [screen_contour], -1, (0, 255, 0), 2)
cv2.imshow("Outline", image)
cv2.waitKey(0)
cv2.destroyAllWindows()
# apply the four point transform to obtain a top-down
# view of the original image
warped = four_point_transform(orig, screen_contour.reshape(4, 2) * ratio)

# convert the warped image to grayscale, then threshold it
# to give it that 'black and white' paper effect
warped = cv2.cvtColor(warped, cv2.COLOR_BGR2GRAY)
T = threshold_local(warped, 11, offset=10, method="gaussian")
warped = (warped > T).astype("uint8") * 255

# show the original and scanned images
print("STEP 3: Apply perspective transform")
cv2.imshow("Original", imutils.resize(orig, height=650))
cv2.imshow("Scanned", imutils.resize(warped, height=650))
cv2.waitKey(0)