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Tutorial Sobel Derivatives

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tribta
2017-08-22 12:28:23 +01:00
parent 3250f11f0c
commit f7d85bfed8
5 changed files with 243 additions and 29 deletions
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samples/cpp/tutorial_code/ImgTrans/Sobel_Demo.cpp
+8 -1
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@@ -30,6 +30,7 @@ int main( int argc, char** argv )
cout << "\nPress 'ESC' to exit program.\nPress 'R' to reset values ( ksize will be -1 equal to Scharr function )";
//![variables]
// First we declare the variables we are going to use
Mat image,src, src_gray;
Mat grad;
const String window_name = "Sobel Demo - Simple Edge Detector";
@@ -40,11 +41,14 @@ int main( int argc, char** argv )
//![variables]
//![load]
String imageName = parser.get<String>("@input"); // by default
String imageName = parser.get<String>("@input");
// As usual we load our source image (src)
image = imread( imageName, IMREAD_COLOR ); // Load an image
// Check if image is loaded fine
if( image.empty() )
{
printf("Error opening image: %s\n", imageName.c_str());
return 1;
}
//![load]
@@ -52,10 +56,12 @@ int main( int argc, char** argv )
for (;;)
{
//![reduce_noise]
// Remove noise by blurring with a Gaussian filter ( kernel size = 3 )
GaussianBlur(image, src, Size(3, 3), 0, 0, BORDER_DEFAULT);
//![reduce_noise]
//![convert_to_gray]
// Convert the image to grayscale
cvtColor(src, src_gray, COLOR_BGR2GRAY);
//![convert_to_gray]
@@ -72,6 +78,7 @@ int main( int argc, char** argv )
//![sobel]
//![convert]
// converting back to CV_8U
convertScaleAbs(grad_x, abs_grad_x);
convertScaleAbs(grad_y, abs_grad_y);
//![convert]
samples/java/tutorial_code/ImgTrans/SobelDemo/SobelDemo.java
+94
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@@ -0,0 +1,94 @@
/**
* @file SobelDemo.java
* @brief Sample code using Sobel and/or Scharr OpenCV functions to make a simple Edge Detector
*/
import org.opencv.core.*;
import org.opencv.highgui.HighGui;
import org.opencv.imgcodecs.Imgcodecs;
import org.opencv.imgproc.Imgproc;
class SobelDemoRun {
public void run(String[] args) {
//! [declare_variables]
// First we declare the variables we are going to use
Mat src, src_gray = new Mat();
Mat grad = new Mat();
String window_name = "Sobel Demo - Simple Edge Detector";
int scale = 1;
int delta = 0;
int ddepth = CvType.CV_16S;
//! [declare_variables]
//! [load]
// As usual we load our source image (src)
// Check number of arguments
if (args.length == 0){
System.out.println("Not enough parameters!");
System.out.println("Program Arguments: [image_path]");
System.exit(-1);
}
// Load the image
src = Imgcodecs.imread(args[0]);
// Check if image is loaded fine
if( src.empty() ) {
System.out.println("Error opening image: " + args[0]);
System.exit(-1);
}
//! [load]
//! [reduce_noise]
// Remove noise by blurring with a Gaussian filter ( kernel size = 3 )
Imgproc.GaussianBlur( src, src, new Size(3, 3), 0, 0, Core.BORDER_DEFAULT );
//! [reduce_noise]
//! [convert_to_gray]
// Convert the image to grayscale
Imgproc.cvtColor( src, src_gray, Imgproc.COLOR_RGB2GRAY );
//! [convert_to_gray]
//! [sobel]
/// Generate grad_x and grad_y
Mat grad_x = new Mat(), grad_y = new Mat();
Mat abs_grad_x = new Mat(), abs_grad_y = new Mat();
/// Gradient X
//Imgproc.Scharr( src_gray, grad_x, ddepth, 1, 0, scale, delta, Core.BORDER_DEFAULT );
Imgproc.Sobel( src_gray, grad_x, ddepth, 1, 0, 3, scale, delta, Core.BORDER_DEFAULT );
/// Gradient Y
//Imgproc.Scharr( src_gray, grad_y, ddepth, 0, 1, scale, delta, Core.BORDER_DEFAULT );
Imgproc.Sobel( src_gray, grad_y, ddepth, 0, 1, 3, scale, delta, Core.BORDER_DEFAULT );
//! [sobel]
//![convert]
// converting back to CV_8U
Core.convertScaleAbs( grad_x, abs_grad_x );
Core.convertScaleAbs( grad_y, abs_grad_y );
//![convert]
//! [add_weighted]
/// Total Gradient (approximate)
Core.addWeighted( abs_grad_x, 0.5, abs_grad_y, 0.5, 0, grad );
//! [add_weighted]
//! [display]
HighGui.imshow( window_name, grad );
HighGui.waitKey(0);
//! [display]
System.exit(0);
}
}
public class SobelDemo {
public static void main(String[] args) {
// Load the native library.
System.loadLibrary(Core.NATIVE_LIBRARY_NAME);
new SobelDemoRun().run(args);
}
}
samples/python/tutorial_code/ImgTrans/SobelDemo/sobel_demo.py
+74
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@@ -0,0 +1,74 @@
"""
@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:])