# Module for processing images with Sobel operator
# Authors FeeLyX, OPyshkin, Esesna
# Version 1.2

import numpy as np
import cv2

# Opening image from file
imginput = cv2.imread('Garceev.jpg', cv2.IMREAD_GRAYSCALE)

# Initializing dimensions of picture
y = len(imginput)
x = len(imginput[0])

# Expanding edges of picture with zeros
imgext = np.zeros((y + 2, x + 2))
for i in range(y):
    for j in range(x):
        imgext[i + 1][j + 1] = imginput[i][j]

# Declaring arrays for processed picture
imgsobelx = np.zeros((y, x))
#imgsobely = np.zeros((y, x))
#imgsobel = np.zeros((y, x))

# Initializing X mask
sobelx = [
    [-1, 0, 1],
    [-2, 0, 2],
    [-1, 0, 1]
    ]

# Initializing Y mask
#sobely = [
#    [-1, -2, -1],
#    [0, 0, 0],
#    [1, 2, 1]
#    ]

# Processing image
for i in range(y):
    for j in range(x):
        piece = np.zeros((3, 3))
        for k in range(3):
            for l in range(3):
                piece[k][l] = imgext[i + k][j + l]
        imgsobelx[i][j] = np.sum(piece * sobelx)
        #imgsobely[i][j] = np.sum(piece * sobely)
        #imgsobel[i][j] = np.sqrt(imgsobelx[i][j] ** 2 +
        #                         imgsobely[i][j] ** 2)

# Writing final pictures into files
cv2.imwrite('sobelx.jpg', imgsobelx)
#cv2.imwrite('sobely.jpg', imgsobely)
#cv2.imwrite('sobel.jpg', imgsobel)

# Waiting for any key pressed to exit
cv2.waitKey(0)
cv2.destroyAllWindows()