update samples: waitKey() usage

Original commit is a5f19f7dd6ae5bc93f73e0417a9e0bfd34c01672

samples/cpp/3calibration.cpp

@@ -351,7 +351,7 @@ int main( int argc, char** argv )
         for( k = 0; k < small_canvas.rows; k += 16 )
             line(small_canvas, Point(0, k), Point(small_canvas.cols, k), Scalar(0,255,0), 1);
         imshow("rectified", small_canvas);
-        int c = waitKey(0);
+        char c = (char)waitKey(0);
         if( c == 27 || c == 'q' || c == 'Q' )
             break;
     }

samples/cpp/calibration.cpp

@@ -493,9 +493,9 @@ int main( int argc, char** argv )
         }
 
         imshow("Image View", view);
-        int key = 0xff & waitKey(capture.isOpened() ? 50 : 500);
+        char key = (char)waitKey(capture.isOpened() ? 50 : 500);
 
-        if( (key & 255) == 27 )
+        if( key == 27 )
             break;
 
         if( key == 'u' && mode == CALIBRATED )
@@ -536,8 +536,8 @@ int main( int argc, char** argv )
             //undistort( view, rview, cameraMatrix, distCoeffs, cameraMatrix );
             remap(view, rview, map1, map2, INTER_LINEAR);
             imshow("Image View", rview);
-            int c = 0xff & waitKey();
-            if( (c & 255) == 27 || c == 'q' || c == 'Q' )
+            char c = (char)waitKey();
+            if( c == 27 || c == 'q' || c == 'Q' )
                 break;
         }
     }

samples/cpp/cloning_gui.cpp

@@ -453,7 +453,7 @@ int main()
 
     for(;;)
     {
-        char key = (char) waitKey(0);
+        char key = (char)waitKey(0);
 
         if(key == 'd' && flag3 == 0)
         {

samples/cpp/convexhull.cpp

@@ -25,7 +25,6 @@ int main( int argc, char** argv )
 
     for(;;)
     {
-        char key;
         int i, count = (unsigned)rng%100 + 1;
 
         vector<Point> points;
@@ -58,7 +57,7 @@ int main( int argc, char** argv )
 
         imshow("hull", img);
 
-        key = (char)waitKey();
+        char key = (char)waitKey();
         if( key == 27 || key == 'q' || key == 'Q' ) // 'ESC'
             break;
     }

samples/cpp/detect_mser.cpp

@@ -279,8 +279,8 @@ static void DrawOpenGLMSER(Mat img, Mat result)
     for (;;)
         {
         updateWindow("OpenGL");
-        int key = waitKey(40);
-        if ((key & 0xff) == 27)
+        char key = (char)waitKey(40);
+        if (key == 27)
             break;
         if (key == 0x20)
             rotateEnable = !rotateEnable;

samples/cpp/distrans.cpp

@@ -133,7 +133,7 @@ int main( int argc, const char** argv )
         // Call to update the view
         onTrackbar(0, 0);
 
-        int c = waitKey(0) & 255;
+        char c = (char)waitKey(0);
 
         if( c == 27 )
             break;

samples/cpp/facedetect.cpp

@@ -72,9 +72,9 @@ int main( int argc, const char** argv )
     }
     if( inputName.empty() || (isdigit(inputName[0]) && inputName.size() == 1) )
     {
-        int c = inputName.empty() ? 0 : inputName[0] - '0';
-        if(!capture.open(c))
-            cout << "Capture from camera #" <<  c << " didn't work" << endl;
+        int camera = inputName.empty() ? 0 : inputName[0] - '0';
+        if(!capture.open(camera))
+            cout << "Capture from camera #" <<  camera << " didn't work" << endl;
     }
     else if( inputName.size() )
     {
@@ -104,7 +104,7 @@ int main( int argc, const char** argv )
             Mat frame1 = frame.clone();
             detectAndDraw( frame1, cascade, nestedCascade, scale, tryflip );
 
-            int c = waitKey(10);
+            char c = (char)waitKey(10);
             if( c == 27 || c == 'q' || c == 'Q' )
                 break;
         }
@@ -127,7 +127,7 @@ int main( int argc, const char** argv )
                 char buf[1000+1];
                 while( fgets( buf, 1000, f ) )
                 {
-                    int len = (int)strlen(buf), c;
+                    int len = (int)strlen(buf);
                     while( len > 0 && isspace(buf[len-1]) )
                         len--;
                     buf[len] = '\0';
@@ -136,7 +136,7 @@ int main( int argc, const char** argv )
                     if( !image.empty() )
                     {
                         detectAndDraw( image, cascade, nestedCascade, scale, tryflip );
-                        c = waitKey(0);
+                        char c = (char)waitKey(0);
                         if( c == 27 || c == 'q' || c == 'Q' )
                             break;
                     }

samples/cpp/ffilldemo.cpp

@@ -105,13 +105,13 @@ int main( int argc, char** argv )
     {
         imshow("image", isColor ? image : gray);
 
-        int c = waitKey(0);
-        if( (c & 255) == 27 )
+        char c = (char)waitKey(0);
+        if( c == 27 )
         {
             cout << "Exiting ...\n";
             break;
         }
-        switch( (char)c )
+        switch( c )
         {
         case 'c':
             if( isColor )

samples/cpp/grabcut.cpp

@@ -306,8 +306,8 @@ int main( int argc, char** argv )
 
     for(;;)
     {
-        int c = waitKey(0);
-        switch( (char) c )
+        char c = (char)waitKey(0);
+        switch( c )
         {
         case '\x1b':
             cout << "Exiting ..." << endl;

samples/cpp/laplace.cpp

@@ -83,10 +83,10 @@ int main( int argc, char** argv )
         convertScaleAbs(laplace, result, (sigma+1)*0.25);
         imshow("Laplacian", result);
 
-        int c = waitKey(30);
+        char c = (char)waitKey(30);
         if( c == ' ' )
             smoothType = smoothType == GAUSSIAN ? BLUR : smoothType == BLUR ? MEDIAN : GAUSSIAN;
-        if( c == 'q' || c == 'Q' || (c & 255) == 27 )
+        if( c == 'q' || c == 'Q' || c == 27 )
             break;
     }
 

samples/cpp/morphology2.cpp

@@ -82,21 +82,19 @@ int main( int argc, char** argv )
 
     for(;;)
     {
-        int c;
-
         OpenClose(open_close_pos, 0);
         ErodeDilate(erode_dilate_pos, 0);
-        c = waitKey(0);
+        char c = (char)waitKey(0);
 
-        if( (char)c == 27 )
+        if( c == 27 )
             break;
-        if( (char)c == 'e' )
+        if( c == 'e' )
             element_shape = MORPH_ELLIPSE;
-        else if( (char)c == 'r' )
+        else if( c == 'r' )
             element_shape = MORPH_RECT;
-        else if( (char)c == 'c' )
+        else if( c == 'c' )
             element_shape = MORPH_CROSS;
-        else if( (char)c == ' ' )
+        else if( c == ' ' )
             element_shape = (element_shape + 1) % 3;
     }
 

samples/cpp/pca.cpp

@@ -183,9 +183,9 @@ int main(int argc, char** argv)
     // display until user presses q
     imshow(winName, reconstruction);
 
-    int key = 0;
+    char key = 0;
     while(key != 'q')
-        key = waitKey();
+        key = (char)waitKey();
 
    return 0;
 }

samples/cpp/phase_corr.cpp

@@ -9,7 +9,7 @@ int main(int, char* [])
 {
     VideoCapture video(0);
     Mat frame, curr, prev, curr64f, prev64f, hann;
-    int key = 0;
+    char key;
 
     do
     {
@@ -37,10 +37,10 @@ int main(int, char* [])
         }
 
         imshow("phase shift", frame);
-        key = waitKey(2);
+        key = (char)waitKey(2);
 
         prev = curr.clone();
-    } while((char)key != 27); // Esc to exit...
+    } while(key != 27); // Esc to exit...
 
     return 0;
 }

samples/cpp/points_classifier.cpp

@@ -312,7 +312,7 @@ int main()
 
     for(;;)
     {
-        uchar key = (uchar)waitKey();
+        char key = (char)waitKey();
 
         if( key == 27 ) break;
 

samples/cpp/segment_objects.cpp

@@ -105,7 +105,7 @@ int main(int argc, char** argv)
         refineSegments(tmp_frame, bgmask, out_frame);
         imshow("video", tmp_frame);
         imshow("segmented", out_frame);
-        int keycode = waitKey(30);
+        char keycode = (char)waitKey(30);
         if( keycode == 27 )
             break;
         if( keycode == ' ' )

samples/cpp/select3dobj.cpp

@@ -285,8 +285,8 @@ static int select3DBox(const string& windowname, const string& selWinName, const
         imshow(windowname, shownFrame);
         imshow(selWinName, selectedObjFrame);
 
-        int c = waitKey(30);
-        if( (c & 255) == 27 )
+        char c = (char)waitKey(30);
+        if( c == 27 )
         {
             nobjpt = 0;
         }
@@ -593,7 +593,7 @@ int main(int argc, char** argv)
 
         imshow("View", shownFrame);
         imshow("Selected Object", selectedObjFrame);
-        int c = waitKey(imageList.empty() && !box.empty() ? 30 : 300);
+        char c = (char)waitKey(imageList.empty() && !box.empty() ? 30 : 300);
         if( c == 'q' || c == 'Q' )
             break;
         if( c == '\r' || c == '\n' )

samples/cpp/smiledetect.cpp

@@ -99,7 +99,7 @@ int main( int argc, const char** argv )
             Mat frame1 = frame.clone();
             detectAndDraw( frame1, cascade, nestedCascade, scale, tryflip );
 
-            int c = waitKey(10);
+            char c = (char)waitKey(10);
             if( c == 27 || c == 'q' || c == 'Q' )
                 break;
         }

samples/cpp/squares.cpp

@@ -167,8 +167,8 @@ int main(int argc, char** argv)
         findSquares(image, squares);
         drawSquares(image, squares);
 
-        int c = waitKey();
-        if( (char)c == 27 )
+        char c = (char)waitKey();
+        if( c == 27 )
             break;
     }
 

samples/cpp/tutorial_code/ImgProc/Pyramids.cpp

@@ -45,26 +45,22 @@ int main( void )
   //![infinite_loop]
   for(;;)
   {
-    int c;
-    c = waitKey(0);
+    char c = (char)waitKey(0);
 
-    if( (char)c == 27 )
+    if( c == 27 )
       { break; }
-    if( (char)c == 'u' )
-      {
-        //![pyrup]
-        pyrUp( tmp, dst, Size( tmp.cols*2, tmp.rows*2 ) );
-        //![pyrup]
+    //![pyrup]
+    if( c == 'u' )
+      { pyrUp( tmp, dst, Size( tmp.cols*2, tmp.rows*2 ) );
         printf( "** Zoom In: Image x 2 \n" );
       }
-    else if( (char)c == 'd' )
-      {
-        //![pyrdown]
-        pyrDown( tmp, dst, Size( tmp.cols/2, tmp.rows/2 ) );
-        //![pyrdown]
+    //![pyrup]
+    //![pyrdown]
+    else if( c == 'd' )
+      { pyrDown( tmp, dst, Size( tmp.cols/2, tmp.rows/2 ) );
         printf( "** Zoom Out: Image / 2 \n" );
       }
-
+    //![pyrdown]
     imshow( window_name, dst );
 
     //![update_tmp]

samples/cpp/tutorial_code/ImgProc/Threshold.cpp

@@ -60,9 +60,8 @@ int main( int, char** argv )
   /// Wait until user finishes program
   for(;;)
     {
-      int c;
-      c = waitKey( 20 );
-      if( (char)c == 27 )
+      char c = (char)waitKey( 20 );
+      if( c == 27 )
     { break; }
     }
 

samples/cpp/tutorial_code/ImgProc/Threshold_inRange.cpp

@@ -41,7 +41,7 @@ int main()
     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);
     //! [trackbar]
-    while(char(waitKey(1))!='q'){
+    while((char)waitKey(1)!='q'){
         //! [while]
         cap>>frame;
         if(frame.empty())

samples/cpp/tutorial_code/ImgTrans/HoughCircle_Demo.cpp

@@ -90,7 +90,7 @@ int main(int argc, char** argv)
     // infinite loop to display
     // and refresh the content of the output image
     // until the user presses q or Q
-    int key = 0;
+    char key = 0;
     while(key != 'q' && key != 'Q')
     {
         // those paramaters cannot be =0
@@ -102,7 +102,7 @@ int main(int argc, char** argv)
         HoughDetection(src_gray, src, cannyThreshold, accumulatorThreshold);
 
         // get user key
-        key = waitKey(10);
+        key = (char)waitKey(10);
     }
 
     return 0;

samples/cpp/tutorial_code/ImgTrans/Remap_Demo.cpp

@@ -40,9 +40,9 @@ int main( int, char** argv )
   for(;;)
   {
     /// Each 1 sec. Press ESC to exit the program
-    int c = waitKey( 1000 );
+    char c = (char)waitKey( 1000 );
 
-    if( (char)c == 27 )
+    if( c == 27 )
       { break; }
 
     /// Update map_x & map_y. Then apply remap

samples/cpp/tutorial_code/ImgTrans/copyMakeBorder_demo.cpp

@@ -23,9 +23,6 @@ RNG rng(12345);
  */
 int main( int, char** argv )
 {
-
-  int c;
-
   //![load]
   src = imread( argv[1], IMREAD_COLOR ); // Load an image
 
@@ -59,13 +56,12 @@ int main( int, char** argv )
   for(;;)
        {
          //![check_keypress]
-         c = waitKey(500);
-
-         if( (char)c == 27 )
+         char c = (char)waitKey(500);
+         if( c == 27 )
            { break; }
-         else if( (char)c == 'c' )
+         else if( c == 'c' )
            { borderType = BORDER_CONSTANT; }
-         else if( (char)c == 'r' )
+         else if( c == 'r' )
            { borderType = BORDER_REPLICATE; }
          //![check_keypress]
 

samples/cpp/tutorial_code/ImgTrans/filter2D_demo.cpp

@@ -25,8 +25,6 @@ int main ( int, char** argv )
   int kernel_size;
   const char* window_name = "filter2D Demo";
 
-  int c;
-
   //![load]
   src = imread( argv[1], IMREAD_COLOR ); // Load an image
 
@@ -45,9 +43,9 @@ int main ( int, char** argv )
   int ind = 0;
   for(;;)
        {
-         c = waitKey(500);
+         char c = (char)waitKey(500);
          /// Press 'ESC' to exit the program
-         if( (char)c == 27 )
+         if( c == 27 )
            { break; }
 
          //![update_kernel]

samples/cpp/tutorial_code/calib3d/real_time_pose_estimation/src/main_detection.cpp

@@ -180,7 +180,7 @@ int main(int argc, char *argv[])
 
   Mat frame, frame_vis;
 
-  while(cap.read(frame) && waitKey(30) != 27) // capture frame until ESC is pressed
+  while(cap.read(frame) && (char)waitKey(30) != 27) // capture frame until ESC is pressed
   {
 
     frame_vis = frame.clone();    // refresh visualisation frame

samples/cpp/tutorial_code/features2D/AKAZE_tracking/planar_tracking.cpp

@@ -195,7 +195,7 @@ int main(int argc, char **argv)
         drawStatistics(orb_res, orb_draw_stats);
         vconcat(akaze_res, orb_res, res_frame);
         cv::imshow(video_name, res_frame);
-        if(cv::waitKey(1)==27) break; //quit on ESC button
+        if(waitKey(1)==27) break; //quit on ESC button
     }
     akaze_stats /= i - 1;
     orb_stats /= i - 1;

samples/cpp/tutorial_code/objectDetection/objectDetection.cpp

@@ -44,8 +44,8 @@ int main( void )
         //-- 3. Apply the classifier to the frame
         detectAndDisplay( frame );
 
-        int c = waitKey(10);
-        if( (char)c == 27 ) { break; } // escape
+        char c = (char)waitKey(10);
+        if( c == 27 ) { break; } // escape
     }
     return 0;
 }

samples/cpp/tutorial_code/objectDetection/objectDetection2.cpp

@@ -51,8 +51,8 @@ int main( void )
         detectAndDisplay( frame );
 
         //-- bail out if escape was pressed
-        int c = waitKey(10);
-        if( (char)c == 27 ) { break; }
+        char c = (char)waitKey(10);
+        if( c == 27 ) { break; }
     }
     return 0;
 }

samples/cpp/tutorial_code/photo/seamless_cloning/cloning_gui.cpp

@@ -452,7 +452,7 @@ int main()
 
     for(;;)
     {
-        char key = (char) waitKey(0);
+        char key = (char)waitKey(0);
 
         if(key == 'd' && flag3 == 0)
         {

samples/cpp/tutorial_code/video/bg_sub.cpp

@@ -23,7 +23,7 @@ using namespace std;
 Mat frame; //current frame
 Mat fgMaskMOG2; //fg mask fg mask generated by MOG2 method
 Ptr<BackgroundSubtractor> pMOG2; //MOG2 Background subtractor
-int keyboard; //input from keyboard
+char keyboard; //input from keyboard
 
 /** Function Headers */
 void help();
@@ -98,7 +98,8 @@ void processVideo(char* videoFilename) {
         exit(EXIT_FAILURE);
     }
     //read input data. ESC or 'q' for quitting
-    while( (char)keyboard != 'q' && (char)keyboard != 27 ){
+    keyboard = 0;
+    while( keyboard != 'q' && keyboard != 27 ){
         //read the current frame
         if(!capture.read(frame)) {
             cerr << "Unable to read next frame." << endl;
@@ -119,7 +120,7 @@ void processVideo(char* videoFilename) {
         imshow("Frame", frame);
         imshow("FG Mask MOG 2", fgMaskMOG2);
         //get the input from the keyboard
-        keyboard = waitKey( 30 );
+        keyboard = (char)waitKey( 30 );
     }
     //delete capture object
     capture.release();
@@ -139,7 +140,8 @@ void processImages(char* fistFrameFilename) {
     //current image filename
     string fn(fistFrameFilename);
     //read input data. ESC or 'q' for quitting
-    while( (char)keyboard != 'q' && (char)keyboard != 27 ){
+    keyboard = 0;
+    while( keyboard != 'q' && keyboard != 27 ){
         //update the background model
         pMOG2->apply(frame, fgMaskMOG2);
         //get the frame number and write it on the current frame
@@ -162,7 +164,7 @@ void processImages(char* fistFrameFilename) {
         imshow("Frame", frame);
         imshow("FG Mask MOG 2", fgMaskMOG2);
         //get the input from the keyboard
-        keyboard = waitKey( 30 );
+        keyboard = (char)waitKey( 30 );
         //search for the next image in the sequence
         ostringstream oss;
         oss << (frameNumber + 1);

samples/cpp/tutorial_code/videoio/video-input-psnr-ssim/video-input-psnr-ssim.cpp

@@ -44,7 +44,6 @@ int main(int argc, char *argv[])
     conv << argv[3] << endl << argv[4];       // put in the strings
     conv >> psnrTriggerValue >> delay;        // take out the numbers
 
-    char c;
     int frameNum = -1;          // Frame counter
 
     VideoCapture captRefrnc(sourceReference), captUndTst(sourceCompareWith);
@@ -126,7 +125,7 @@ int main(int argc, char *argv[])
         imshow(WIN_RF, frameReference);
         imshow(WIN_UT, frameUnderTest);
 
-        c = (char)waitKey(delay);
+        char c = (char)waitKey(delay);
         if (c == 27) break;
     }
 

samples/cpp/watershed.cpp

@@ -74,19 +74,19 @@ int main( int argc, char** argv )
 
     for(;;)
     {
-        int c = waitKey(0);
+        char c = (char)waitKey(0);
 
-        if( (char)c == 27 )
+        if( c == 27 )
             break;
 
-        if( (char)c == 'r' )
+        if( c == 'r' )
         {
             markerMask = Scalar::all(0);
             img0.copyTo(img);
             imshow( "image", img );
         }
 
-        if( (char)c == 'w' || (char)c == ' ' )
+        if( c == 'w' || c == ' ' )
         {
             int i, j, compCount = 0;
             vector<vector<Point> > contours;