Tutorial Sobel Derivatives

samples/python/tutorial_code/ImgTrans/SobelDemo/sobel_demo.py

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+"""
+@file sobel_demo.py
+@brief Sample code using Sobel and/or Scharr OpenCV functions to make a simple Edge Detector
+"""
+import sys
+import cv2
+
+
+def main(argv):
+    ## [variables]
+    # First we declare the variables we are going to use
+    window_name = ('Sobel Demo - Simple Edge Detector')
+    scale = 1
+    delta = 0
+    ddepth = cv2.CV_16S
+    ## [variables]
+
+    ## [load]
+    # As usual we load our source image (src)
+    # Check number of arguments
+    if len(argv) < 1:
+        print ('Not enough parameters')
+        print ('Usage:\nmorph_lines_detection.py < path_to_image >')
+        return -1
+
+    # Load the image
+    src = cv2.imread(argv[0], cv2.IMREAD_COLOR)
+
+    # Check if image is loaded fine
+    if src is None:
+        print ('Error opening image: ' + argv[0])
+        return -1
+    ## [load]
+
+    ## [reduce_noise]
+    # Remove noise by blurring with a Gaussian filter ( kernel size = 3 )
+    src = cv2.GaussianBlur(src, (3, 3), 0)
+    ## [reduce_noise]
+
+    ## [convert_to_gray]
+    # Convert the image to grayscale
+    gray = cv2.cvtColor(src, cv2.COLOR_BGR2GRAY)
+    ## [convert_to_gray]
+
+    ## [sobel]
+    # Gradient-X
+    # grad_x = cv2.Scharr(gray,ddepth,1,0)
+    grad_x = cv2.Sobel(gray, ddepth, 1, 0, ksize=3, scale=scale, delta=delta, borderType=cv2.BORDER_DEFAULT)
+
+    # Gradient-Y
+    # grad_y = cv2.Scharr(gray,ddepth,0,1)
+    grad_y = cv2.Sobel(gray, ddepth, 0, 1, ksize=3, scale=scale, delta=delta, borderType=cv2.BORDER_DEFAULT)
+    ## [sobel]
+
+    ## [convert]
+    # converting back to uint8
+    abs_grad_x = cv2.convertScaleAbs(grad_x)
+    abs_grad_y = cv2.convertScaleAbs(grad_y)
+    ## [convert]
+
+    ## [blend]
+    ## Total Gradient (approximate)
+    grad = cv2.addWeighted(abs_grad_x, 0.5, abs_grad_y, 0.5, 0)
+    ## [blend]
+
+    ## [display]
+    cv2.imshow(window_name, grad)
+    cv2.waitKey(0)
+    ## [display]
+
+    return 0
+
+if __name__ == "__main__":
+    main(sys.argv[1:])