opencv_032.py

import cv2 as cv
import numpy as np

src = cv.imread("./test.png")
cv.namedWindow("input", cv.WINDOW_AUTOSIZE)
cv.imshow("input", src)

robert_x = np.array([[1, 0],[0, -1]], dtype=np.float32)
robert_y = np.array([[0, -1],[1, 0]], dtype=np.float32)

prewitt_x = np.array([[-1, 0, 1], [-1, 0, 1], [-1, 0, 1]], dtype=np.float32)
prewitt_y = np.array([[-1, -1, -1], [0, 0, 0], [1, 1, 1]], dtype=np.float32)

robert_grad_x = cv.filter2D(src, cv.CV_16S, robert_x)
robert_grad_y = cv.filter2D(src, cv.CV_16S, robert_y)
robert_grad_x = cv.convertScaleAbs(robert_grad_x)
robert_grad_y = cv.convertScaleAbs(robert_grad_y)

prewitt_grad_x = cv.filter2D(src, cv.CV_32F, prewitt_x)
prewitt_grad_y = cv.filter2D(src, cv.CV_32F, prewitt_y)
prewitt_grad_x = cv.convertScaleAbs(prewitt_grad_x)
prewitt_grad_y = cv.convertScaleAbs(prewitt_grad_y)

# cv.imshow("robert x", robert_grad_x);
# cv.imshow("robert y", robert_grad_y);
# cv.imshow("prewitt x", prewitt_grad_x);
# cv.imshow("prewitt y", prewitt_grad_y);

h, w = src.shape[:2]
robert_result = np.zeros([h, w*2, 3], dtype=src.dtype)
robert_result[0:h,0:w,:] = robert_grad_x
robert_result[0:h,w:2*w,:] = robert_grad_y
cv.imshow("robert_result", robert_result)

prewitt_result = np.zeros([h, w*2, 3], dtype=src.dtype)
prewitt_result[0:h,0:w,:] = prewitt_grad_x
prewitt_result[0:h,w:2*w,:] = prewitt_grad_y
cv.imshow("prewitt_result", prewitt_result)

cv.imwrite("./prewitt.png", prewitt_result)
cv.imwrite("./robert.png", robert_result)

cv.waitKey(0)
cv.destroyAllWindows()