Merge pull request #11543 from catree:add_tutorial_imgproc_java_python

samples/cpp/tutorial_code/ImgProc/Threshold.cpp

@@ -7,8 +7,10 @@
 #include "opencv2/imgproc.hpp"
 #include "opencv2/imgcodecs.hpp"
 #include "opencv2/highgui.hpp"
+#include <iostream>
 
 using namespace cv;
+using std::cout;
 
 /// Global variables
 
@@ -16,7 +18,7 @@ int threshold_value = 0;
 int threshold_type = 3;
 int const max_value = 255;
 int const max_type = 4;
-int const max_BINARY_value = 255;
+int const max_binary_value = 255;
 
 Mat src, src_gray, dst;
 const char* window_name = "Threshold Demo";
@@ -24,69 +26,62 @@ const char* window_name = "Threshold Demo";
 const char* trackbar_type = "Type: \n 0: Binary \n 1: Binary Inverted \n 2: Truncate \n 3: To Zero \n 4: To Zero Inverted";
 const char* trackbar_value = "Value";
 
-/// Function headers
-void Threshold_Demo( int, void* );
+//![Threshold_Demo]
+/**
+ * @function Threshold_Demo
+ */
+static void Threshold_Demo( int, void* )
+{
+    /* 0: Binary
+     1: Binary Inverted
+     2: Threshold Truncated
+     3: Threshold to Zero
+     4: Threshold to Zero Inverted
+    */
+    threshold( src_gray, dst, threshold_value, max_binary_value, threshold_type );
+    imshow( window_name, dst );
+}
+//![Threshold_Demo]
 
 /**
  * @function main
  */
 int main( int argc, char** argv )
 {
-  //! [load]
-  String imageName("../data/stuff.jpg"); // by default
-  if (argc > 1)
-  {
-      imageName = argv[1];
-  }
-  src = imread( imageName, IMREAD_COLOR ); // Load an image
-
-  if( src.empty() )
-    { return -1; }
-
-  cvtColor( src, src_gray, COLOR_BGR2GRAY ); // Convert the image to Gray
-  //! [load]
-
-  //! [window]
-  namedWindow( window_name, WINDOW_AUTOSIZE ); // Create a window to display results
-  //! [window]
-
-  //! [trackbar]
-  createTrackbar( trackbar_type,
-                  window_name, &threshold_type,
-                  max_type, Threshold_Demo ); // Create Trackbar to choose type of Threshold
-
-  createTrackbar( trackbar_value,
-                  window_name, &threshold_value,
-                  max_value, Threshold_Demo ); // Create Trackbar to choose Threshold value
-  //! [trackbar]
-
-  Threshold_Demo( 0, 0 ); // Call the function to initialize
-
-  /// Wait until user finishes program
-  for(;;)
+    //! [load]
+    String imageName("../data/stuff.jpg"); // by default
+    if (argc > 1)
     {
-      char c = (char)waitKey( 20 );
-      if( c == 27 )
-    { break; }
+        imageName = argv[1];
+    }
+    src = imread( imageName, IMREAD_COLOR ); // Load an image
+
+    if (src.empty())
+    {
+        cout << "Cannot read image: " << imageName << std::endl;
+        return -1;
     }
 
+    cvtColor( src, src_gray, COLOR_BGR2GRAY ); // Convert the image to Gray
+    //! [load]
+
+    //! [window]
+    namedWindow( window_name, WINDOW_AUTOSIZE ); // Create a window to display results
+    //! [window]
+
+    //! [trackbar]
+    createTrackbar( trackbar_type,
+                    window_name, &threshold_type,
+                    max_type, Threshold_Demo ); // Create Trackbar to choose type of Threshold
+
+    createTrackbar( trackbar_value,
+                    window_name, &threshold_value,
+                    max_value, Threshold_Demo ); // Create Trackbar to choose Threshold value
+    //! [trackbar]
+
+    Threshold_Demo( 0, 0 ); // Call the function to initialize
+
+    /// Wait until user finishes program
+    waitKey();
+    return 0;
 }
-
-//![Threshold_Demo]
-/**
- * @function Threshold_Demo
- */
-void Threshold_Demo( int, void* )
-{
-  /* 0: Binary
-     1: Binary Inverted
-     2: Threshold Truncated
-     3: Threshold to Zero
-     4: Threshold to Zero Inverted
-   */
-
-  threshold( src_gray, dst, threshold_value, max_BINARY_value,threshold_type );
-
-  imshow( window_name, dst );
-}
-//![Threshold_Demo]

samples/cpp/tutorial_code/ImgProc/Threshold_inRange.cpp

@@ -1,102 +1,104 @@
 #include "opencv2/imgproc.hpp"
 #include "opencv2/highgui.hpp"
-
 #include <iostream>
-#include <stdlib.h>
 
-using namespace std;
 using namespace cv;
 
-/** Function Headers */
-void on_low_r_thresh_trackbar(int, void *);
-void on_high_r_thresh_trackbar(int, void *);
-void on_low_g_thresh_trackbar(int, void *);
-void on_high_g_thresh_trackbar(int, void *);
-void on_low_b_thresh_trackbar(int, void *);
-void on_high_b_thresh_trackbar(int, void *);
-
 /** Global Variables */
-int low_r=30, low_g=30, low_b=30;
-int high_r=100, high_g=100, high_b=100;
+const int max_value_H = 360/2;
+const int max_value = 255;
+const String window_capture_name = "Video Capture";
+const String window_detection_name = "Object Detection";
+int low_H = 0, low_S = 0, low_V = 0;
+int high_H = max_value_H, high_S = max_value, high_V = max_value;
 
-/** @function main */
-int main()
+//! [low]
+static void on_low_H_thresh_trackbar(int, void *)
+{
+    low_H = min(high_H-1, low_H);
+    setTrackbarPos("Low H", window_detection_name, low_H);
+}
+//! [low]
+
+//! [high]
+static void on_high_H_thresh_trackbar(int, void *)
+{
+    high_H = max(high_H, low_H+1);
+    setTrackbarPos("High H", window_detection_name, high_H);
+}
+
+//! [high]
+static void on_low_S_thresh_trackbar(int, void *)
+{
+    low_S = min(high_S-1, low_S);
+    setTrackbarPos("Low S", window_detection_name, low_S);
+}
+
+static void on_high_S_thresh_trackbar(int, void *)
+{
+    high_S = max(high_S, low_S+1);
+    setTrackbarPos("High S", window_detection_name, high_S);
+}
+
+static void on_low_V_thresh_trackbar(int, void *)
+{
+    low_V = min(high_V-1, low_V);
+    setTrackbarPos("Low V", window_detection_name, low_V);
+}
+
+static void on_high_V_thresh_trackbar(int, void *)
+{
+    high_V = max(high_V, low_V+1);
+    setTrackbarPos("High V", window_detection_name, high_V);
+}
+
+int main(int argc, char* argv[])
 {
-    //! [mat]
-    Mat frame, frame_threshold;
-    //! [mat]
     //! [cap]
-    VideoCapture cap(0);
+    VideoCapture cap(argc > 1 ? atoi(argv[1]) : 0);
     //! [cap]
+
     //! [window]
-    namedWindow("Video Capture", WINDOW_NORMAL);
-    namedWindow("Object Detection", WINDOW_NORMAL);
+    namedWindow(window_capture_name);
+    namedWindow(window_detection_name);
     //! [window]
+
     //! [trackbar]
-    //-- Trackbars to set thresholds for RGB values
-    createTrackbar("Low R","Object Detection", &low_r, 255, on_low_r_thresh_trackbar);
-    createTrackbar("High R","Object Detection", &high_r, 255, on_high_r_thresh_trackbar);
-    createTrackbar("Low G","Object Detection", &low_g, 255, on_low_g_thresh_trackbar);
-    createTrackbar("High G","Object Detection", &high_g, 255, on_high_g_thresh_trackbar);
-    createTrackbar("Low B","Object Detection", &low_b, 255, on_low_b_thresh_trackbar);
-    createTrackbar("High B","Object Detection", &high_b, 255, on_high_b_thresh_trackbar);
+    // Trackbars to set thresholds for HSV values
+    createTrackbar("Low H", window_detection_name, &low_H, max_value_H, on_low_H_thresh_trackbar);
+    createTrackbar("High H", window_detection_name, &high_H, max_value_H, on_high_H_thresh_trackbar);
+    createTrackbar("Low S", window_detection_name, &low_S, max_value, on_low_S_thresh_trackbar);
+    createTrackbar("High S", window_detection_name, &high_S, max_value, on_high_S_thresh_trackbar);
+    createTrackbar("Low V", window_detection_name, &low_V, max_value, on_low_V_thresh_trackbar);
+    createTrackbar("High V", window_detection_name, &high_V, max_value, on_high_V_thresh_trackbar);
     //! [trackbar]
-    while((char)waitKey(1)!='q'){
+
+    Mat frame, frame_HSV, frame_threshold;
+    while (true) {
         //! [while]
-        cap>>frame;
+        cap >> frame;
         if(frame.empty())
+        {
             break;
-        //-- Detect the object based on RGB Range Values
-        inRange(frame,Scalar(low_b,low_g,low_r), Scalar(high_b,high_g,high_r),frame_threshold);
+        }
+
+        // Convert from BGR to HSV colorspace
+        cvtColor(frame, frame_HSV, COLOR_BGR2HSV);
+        // Detect the object based on HSV Range Values
+        inRange(frame_HSV, Scalar(low_H, low_S, low_V), Scalar(high_H, high_S, high_V), frame_threshold);
         //! [while]
+
         //! [show]
-        //-- Show the frames
-        imshow("Video Capture",frame);
-        imshow("Object Detection",frame_threshold);
+        // Show the frames
+        imshow(window_capture_name, frame);
+        imshow(window_detection_name, frame_threshold);
         //! [show]
+
+        char key = (char) waitKey(30);
+        if (key == 'q' || key == 27)
+        {
+            break;
+        }
     }
     return 0;
 }
-//! [low]
-/** @function on_low_r_thresh_trackbar */
-void on_low_r_thresh_trackbar(int, void *)
-{
-    low_r = min(high_r-1, low_r);
-    setTrackbarPos("Low R","Object Detection", low_r);
-}
-//! [low]
-//! [high]
-/** @function on_high_r_thresh_trackbar */
-void on_high_r_thresh_trackbar(int, void *)
-{
-    high_r = max(high_r, low_r+1);
-    setTrackbarPos("High R", "Object Detection", high_r);
-}
-//![high]
-/** @function on_low_g_thresh_trackbar */
-void on_low_g_thresh_trackbar(int, void *)
-{
-    low_g = min(high_g-1, low_g);
-    setTrackbarPos("Low G","Object Detection", low_g);
-}
-
-/** @function on_high_g_thresh_trackbar */
-void on_high_g_thresh_trackbar(int, void *)
-{
-    high_g = max(high_g, low_g+1);
-    setTrackbarPos("High G", "Object Detection", high_g);
-}
-
-/** @function on_low_b_thresh_trackbar */
-void on_low_b_thresh_trackbar(int, void *)
-{
-    low_b= min(high_b-1, low_b);
-    setTrackbarPos("Low B","Object Detection", low_b);
-}
-
-/** @function on_high_b_thresh_trackbar */
-void on_high_b_thresh_trackbar(int, void *)
-{
-    high_b = max(high_b, low_b+1);
-    setTrackbarPos("High B", "Object Detection", high_b);
-}

samples/cpp/tutorial_code/ImgTrans/CannyDetector_Demo.cpp

@@ -14,11 +14,10 @@ using namespace cv;
 Mat src, src_gray;
 Mat dst, detected_edges;
 
-int edgeThresh = 1;
-int lowThreshold;
-int const max_lowThreshold = 100;
-int ratio = 3;
-int kernel_size = 3;
+int lowThreshold = 0;
+const int max_lowThreshold = 100;
+const int ratio = 3;
+const int kernel_size = 3;
 const char* window_name = "Edge Map";
 //![variables]
 

samples/cpp/tutorial_code/ImgTrans/Remap_Demo.cpp

@@ -11,90 +11,104 @@
 
 using namespace cv;
 
-/// Global variables
-Mat src, dst;
-Mat map_x, map_y;
-const char* remap_window = "Remap demo";
-int ind = 0;
-
 /// Function Headers
-void update_map( void );
+void update_map( int &ind, Mat &map_x, Mat &map_y );
 
 /**
  * @function main
  */
 int main(int argc, const char** argv)
 {
-  /// Load the image
-  CommandLineParser parser(argc, argv, "{@image |../data/chicky_512.png|input image name}");
-  std::string filename = parser.get<std::string>(0);
-  src = imread( filename, IMREAD_COLOR );
+    CommandLineParser parser(argc, argv, "{@image |../data/chicky_512.png|input image name}");
+    std::string filename = parser.get<std::string>(0);
+    //! [Load]
+    /// Load the image
+    Mat src = imread( filename, IMREAD_COLOR );
+    if (src.empty())
+    {
+        std::cout << "Cannot read image: " << filename << std::endl;
+        return -1;
+    }
+    //! [Load]
 
-  /// Create dst, map_x and map_y with the same size as src:
-  dst.create( src.size(), src.type() );
-  map_x.create( src.size(), CV_32FC1 );
-  map_y.create( src.size(), CV_32FC1 );
+    //! [Create]
+    /// Create dst, map_x and map_y with the same size as src:
+    Mat dst(src.size(), src.type());
+    Mat map_x(src.size(), CV_32FC1);
+    Mat map_y(src.size(), CV_32FC1);
+    //! [Create]
 
-  /// Create window
-  namedWindow( remap_window, WINDOW_AUTOSIZE );
+    //! [Window]
+    /// Create window
+    const char* remap_window = "Remap demo";
+    namedWindow( remap_window, WINDOW_AUTOSIZE );
+    //! [Window]
 
-  /// Loop
-  for(;;)
-  {
-    /// Each 1 sec. Press ESC to exit the program
-    char c = (char)waitKey( 1000 );
+    //! [Loop]
+    /// Index to switch between the remap modes
+    int ind = 0;
+    for(;;)
+    {
+        /// Update map_x & map_y. Then apply remap
+        update_map(ind, map_x, map_y);
+        remap( src, dst, map_x, map_y, INTER_LINEAR, BORDER_CONSTANT, Scalar(0, 0, 0) );
 
-    if( c == 27 )
-      { break; }
+        /// Display results
+        imshow( remap_window, dst );
 
-    /// Update map_x & map_y. Then apply remap
-    update_map();
-    remap( src, dst, map_x, map_y, INTER_LINEAR, BORDER_CONSTANT, Scalar(0, 0, 0) );
-
-    // Display results
-    imshow( remap_window, dst );
-  }
-  return 0;
+        /// Each 1 sec. Press ESC to exit the program
+        char c = (char)waitKey( 1000 );
+        if( c == 27 )
+        {
+            break;
+        }
+    }
+    //! [Loop]
+    return 0;
 }
 
 /**
  * @function update_map
  * @brief Fill the map_x and map_y matrices with 4 types of mappings
  */
-void update_map( void )
+//! [Update]
+void update_map( int &ind, Mat &map_x, Mat &map_y )
 {
-  ind = ind%4;
-
-  for( int j = 0; j < src.rows; j++ )
-    { for( int i = 0; i < src.cols; i++ )
-     {
-           switch( ind )
-         {
-         case 0:
-           if( i > src.cols*0.25 && i < src.cols*0.75 && j > src.rows*0.25 && j < src.rows*0.75 )
-                 {
-               map_x.at<float>(j,i) = 2*( i - src.cols*0.25f ) + 0.5f ;
-               map_y.at<float>(j,i) = 2*( j - src.rows*0.25f ) + 0.5f ;
-              }
-           else
-         { map_x.at<float>(j,i) = 0 ;
-               map_y.at<float>(j,i) = 0 ;
-                 }
-                   break;
-         case 1:
-               map_x.at<float>(j,i) = (float)i ;
-               map_y.at<float>(j,i) = (float)(src.rows - j) ;
-           break;
-             case 2:
-               map_x.at<float>(j,i) = (float)(src.cols - i) ;
-               map_y.at<float>(j,i) = (float)j ;
-           break;
-             case 3:
-               map_x.at<float>(j,i) = (float)(src.cols - i) ;
-               map_y.at<float>(j,i) = (float)(src.rows - j) ;
-           break;
-             } // end of switch
-     }
+    for( int i = 0; i < map_x.rows; i++ )
+    {
+        for( int j = 0; j < map_x.cols; j++ )
+        {
+            switch( ind )
+            {
+            case 0:
+                if( j > map_x.cols*0.25 && j < map_x.cols*0.75 && i > map_x.rows*0.25 && i < map_x.rows*0.75 )
+                {
+                    map_x.at<float>(i, j) = 2*( j - map_x.cols*0.25f ) + 0.5f;
+                    map_y.at<float>(i, j) = 2*( i - map_x.rows*0.25f ) + 0.5f;
+                }
+                else
+                {
+                    map_x.at<float>(i, j) = 0;
+                    map_y.at<float>(i, j) = 0;
+                }
+                break;
+            case 1:
+                map_x.at<float>(i, j) = (float)j;
+                map_y.at<float>(i, j) = (float)(map_x.rows - i);
+                break;
+            case 2:
+                map_x.at<float>(i, j) = (float)(map_x.cols - j);
+                map_y.at<float>(i, j) = (float)i;
+                break;
+            case 3:
+                map_x.at<float>(i, j) = (float)(map_x.cols - j);
+                map_y.at<float>(i, j) = (float)(map_x.rows - i);
+                break;
+            default:
+                break;
+            } // end of switch
+        }
     }
-  ind++;
+    ind = (ind+1) % 4;
 }
+//! [Update]