adding waitChar key to remove issues with waitKey char comparisons

done for cpp/markdown/python filters on search function

also added wrapped functionality for Python
then checked all python samples, removed ord() and 0xFF anding  - no longer needed -

apps/createsamples/utility.cpp

@@ -1270,7 +1270,7 @@ void cvCreateTrainingSamples( const char* filename,
                 if( showsamples )
                 {
                     cvShowImage( "Sample", &sample );
-                    if( cvWaitKey( 0 ) == 27 )
+                    if( (cvWaitKey( 0 ) & 0xFF) == 27 )
                     {
                         showsamples = 0;
                     }
@@ -1402,7 +1402,7 @@ void cvCreateTestSamples( const char* infoname,
                 if( showsamples )
                 {
                     cvShowImage( "Image", &cvbgreader->src );
-                    if( cvWaitKey( 0 ) == 27 )
+                    if( (cvWaitKey( 0 ) & 0xFF) == 27 )
                     {
                         showsamples = 0;
                     }
@@ -1525,7 +1525,7 @@ int cvCreateTrainingSamplesFromInfo( const char* infoname, const char* vecfilena
             if( showsamples )
             {
                 cvShowImage( "Sample", sample );
-                if( cvWaitKey( 0 ) == 27 )
+                if( (cvWaitKey( 0 ) & 0xFF) == 27 )
                 {
                     showsamples = 0;
                 }
@@ -1672,7 +1672,7 @@ void cvShowVecSamples( const char* filename, int winwidth, int winheight,
                 icvGetTraininDataFromVec( sample, &file );
                 if( scale != 1.0 ) cvResize( sample, scaled_sample, CV_INTER_LINEAR);
                 cvShowImage( "Sample", scaled_sample );
-                if( cvWaitKey( 0 ) == 27 ) break;
+                if( (cvWaitKey( 0 ) & 0xFF) == 27 ) break;
             }
             if( scaled_sample && scaled_sample != sample ) cvReleaseMat( &scaled_sample );
             cvReleaseMat( &sample );

apps/interactive-calibration/calibPipeline.cpp

@@ -62,7 +62,7 @@ PipelineExitStatus CalibPipeline::start(std::vector<cv::Ptr<FrameProcessor> > pr
         for (std::vector<cv::Ptr<FrameProcessor> >::iterator it = processors.begin(); it != processors.end(); ++it)
             processedFrame = (*it)->processFrame(processedFrame);
         cv::imshow(mainWindowName, processedFrame);
-        int key = cv::waitKey(CAP_DELAY);
+        char key = cv::waitChar(CAP_DELAY);
 
         if(key == 27) // esc
             return Finished;

doc/tutorials/imgproc/imgtrans/remap/remap.markdown

@@ -85,9 +85,9 @@ Explanation
     while( true )
     {
       /// Each 1 sec. Press ESC to exit the program
-      int c = waitKey( 1000 );
+      char c = waitChar( 1000 );
 
-      if( (char)c == 27 )
+      if( c == 27 )
         { break; }
 
       /// Update map_x & map_y. Then apply remap

doc/tutorials/imgproc/pyramids/pyramids.markdown

@@ -93,6 +93,7 @@ Let's check the general structure of the program:
 
 -   Perform an infinite loop waiting for user input.
     @snippet cpp/tutorial_code/ImgProc/Pyramids.cpp infinite_loop
+
     Our program exits if the user presses *ESC*. Besides, it has two options:
 
     -   **Perform upsampling (after pressing 'u')**

modules/highgui/include/opencv2/highgui.hpp

@@ -109,7 +109,7 @@ It provides easy interface to:
 
             Mat img2,img3;
 
-            while( waitKey(33) != 27 )
+            while( waitChar(33) != 27 )
             {
                 img1.convertTo(img2,-1,1,value);
                 video >> img3;
@@ -338,6 +338,26 @@ If there are several HighGUI windows, any of them can be active.
  */
 CV_EXPORTS_W int waitKey(int delay = 0);
 
+/** @brief Waits for a pressed key and returns the corresponding char value (ASCII) assigned.
+
+The function waitChar waits for a key event infinitely (when \f$\texttt{delay}\leq 0\f$ ) or for delay
+milliseconds, when it is positive. It returns the ASCII code of the pressed key as a char value. If no key was pressed before
+the specified time has elapsed, -1 (most systems) or 255 (if char == unsigned char) is returned depending on the system available.
+
+@note
+
+There is a minor issue for `char == unsigned char systems`. Return value or timeout could be mixed up with value of valid `'\0xFF'` symbol.
+However this is an extremely rare usecase, and is thus ignored for the moment.
+
+@note
+
+The function only works if there is at least one HighGUI window created and the window is active.
+If there are several HighGUI windows, any of them can be active.
+
+@param delay Delay in milliseconds. 0 is the special value that means "forever".
+ */
+CV_EXPORTS_W char waitChar(int delay = 0);
+
 /** @brief Displays an image in the specified window.
 
 The function imshow displays an image in the specified window. If the window was created with the

modules/highgui/src/window.cpp

@@ -198,6 +198,15 @@ int cv::waitKey(int delay)
     return cvWaitKey(delay);
 }
 
+char cv::waitChar(int delay){
+#if CHAR_MIN==SCHAR_MIN
+    int intKey = cv::waitKey(delay) & 0xFF;
+    return (char)(intKey & 0x80 ? intKey - 0x100 : intKey);
+#else
+    return (char)(cv::waitKey(delay) & 0xff);
+#endif
+}
+
 int cv::createTrackbar(const String& trackbarName, const String& winName,
                    int* value, int count, TrackbarCallback callback,
                    void* userdata)

modules/python/src2/cv2.cpp

@@ -542,6 +542,12 @@ bool pyopencv_to(PyObject* obj, double& value, const char* name)
     return !PyErr_Occurred();
 }
 
+template<>
+PyObject* pyopencv_from(const char& value)
+{
+    return PyInt_FromLong(value);
+}
+
 template<>
 PyObject* pyopencv_from(const float& value)
 {

modules/python/test/tst_scene_render.py

@@ -113,7 +113,7 @@ if __name__ == '__main__':
         img = render.getNextFrame()
         cv2.imshow('img', img)
 
-        ch = 0xFF & cv2.waitKey(3)
+        ch = cv2.waitChar(3)
         if  ch == 27:
             break
     cv2.destroyAllWindows()

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 = waitChar(0);
         if( c == 27 || c == 'q' || c == 'Q' )
             break;
     }

samples/cpp/autofocus.cpp

@@ -400,7 +400,7 @@ int main(int argc, char ** argv)
         }
 
         imshow(windowOriginal, frame);
-        switch (key = static_cast<char>(waitKey(30)))
+        switch (key = waitChar(30))
         {
             case 'k': // focus out
                 cap.set(CAP_PROP_ZOOM, 100);

samples/cpp/bgfg_segm.cpp

@@ -95,7 +95,7 @@ int main(int argc, const char** argv)
         if(!bgimg.empty())
           imshow("mean background image", bgimg );
 
-        char k = (char)waitKey(30);
+        char k = waitChar(30);
         if( k == 27 ) break;
         if( k == ' ' )
         {

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 = waitChar(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();
+            char c = waitChar();
-            if( (c & 255) == 27 || c == 'q' || c == 'Q' )
+            if( c == 27 || c == 'q' || c == 'Q' )
                 break;
         }
     }

samples/cpp/camshiftdemo.cpp

@@ -188,7 +188,7 @@ int main( int argc, const char** argv )
         imshow( "CamShift Demo", image );
         imshow( "Histogram", histimg );
 
-        char c = (char)waitKey(10);
+        char c = waitChar(10);
         if( c == 27 )
             break;
         switch(c)

samples/cpp/cloning_gui.cpp

@@ -453,7 +453,7 @@ int main()
 
     for(;;)
     {
-        char key = (char) waitKey(0);
+        char key = waitChar(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 = waitChar();
         if( key == 27 || key == 'q' || key == 'Q' ) // 'ESC'
             break;
     }

samples/cpp/detect_mser.cpp

@@ -277,8 +277,8 @@ static void DrawOpenGLMSER(Mat img, Mat result)
     for (;;)
         {
         updateWindow("OpenGL");
-        int key = waitKey(40);
+        char key = waitChar(40);
-        if ((key & 0xff) == 27)
+        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 = waitChar(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';
+        int camera = inputName.empty() ? 0 : inputName[0] - '0';
-        if(!capture.open(c))
+        if(!capture.open(camera))
-            cout << "Capture from camera #" <<  c << " didn't work" << endl;
+            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 = waitChar(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 = waitChar(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);
+        char c = waitChar(0);
-        if( (c & 255) == 27 )
+        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);
+        char c = waitChar(0);
-        switch( (char) c )
+        switch( c )
         {
         case '\x1b':
             cout << "Exiting ..." << endl;

samples/cpp/image_sequence.cpp

@@ -57,7 +57,7 @@ int main(int argc, char** argv)
 
         imshow("Image sequence | press ESC to close", image);
 
-        if(waitKey(500) == 27)
+        if( waitChar(500) == 27)
             break;
     }
 

samples/cpp/inpaint.cpp

@@ -71,7 +71,7 @@ int main( int argc, char** argv )
 
     for(;;)
     {
-        char c = (char)waitKey();
+        char c = waitChar();
 
         if( c == 27 )
             break;

samples/cpp/kalman.cpp

@@ -35,7 +35,7 @@ int main(int, char**)
     Mat state(2, 1, CV_32F); /* (phi, delta_phi) */
     Mat processNoise(2, 1, CV_32F);
     Mat measurement = Mat::zeros(1, 1, CV_32F);
-    char code = (char)-1;
+    char code = 0;
 
     for(;;)
     {
@@ -89,7 +89,7 @@ int main(int, char**)
             state = KF.transitionMatrix*state + processNoise;
 
             imshow( "Kalman", img );
-            code = (char)waitKey(100);
+            code = waitChar(100);
 
             if( code > 0 )
                 break;

samples/cpp/kmeans.cpp

@@ -68,7 +68,7 @@ int main( int /*argc*/, char** /*argv*/ )
 
         imshow("clusters", img);
 
-        char key = (char)waitKey();
+        char key = waitChar();
         if( key == 27 || key == 'q' || key == 'Q' ) // 'ESC'
             break;
     }

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 = waitChar(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/lkdemo.cpp

@@ -131,7 +131,7 @@ int main( int argc, char** argv )
         needToInit = false;
         imshow("LK Demo", image);
 
-        char c = (char)waitKey(10);
+        char c = waitChar(10);
         if( c == 27 )
             break;
         switch( c )

samples/cpp/minarea.cpp

@@ -72,7 +72,7 @@ int main( int /*argc*/, char** /*argv*/ )
 
         imshow( "Rectangle, triangle & circle", img );
 
-        char key = (char)waitKey();
+        char key = waitChar();
         if( key == 27 || key == 'q' || key == 'Q' ) // 'ESC'
             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 = waitChar(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 = waitChar();
 
    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 = waitChar(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 = waitChar();
 
         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 = waitChar(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);
+        char c = waitChar(30);
-        if( (c & 255) == 27 )
+        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 = waitChar(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 = waitChar(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();
+        char c = waitChar();
-        if( (char)c == 27 )
+        if( c == 27 )
             break;
     }
 

samples/cpp/starter_video.cpp

@@ -50,7 +50,7 @@ namespace {
                 break;
 
             imshow(window_name, frame);
-            char key = (char)waitKey(30); //delay N millis, usually long enough to display and capture input
+            char key = waitChar(30); //delay N millis, usually long enough to display and capture input
 
             switch (key) {
             case 'q':

samples/cpp/stereo_calib.cpp

@@ -122,7 +122,7 @@ StereoCalib(const vector<string>& imagelist, Size boardSize, float squareSize, b
                 double sf = 640./MAX(img.rows, img.cols);
                 resize(cimg, cimg1, Size(), sf, sf);
                 imshow("corners", cimg1);
-                char c = (char)waitKey(500);
+                char c = waitChar(500);
                 if( c == 27 || c == 'q' || c == 'Q' ) //Allow ESC to quit
                     exit(-1);
             }
@@ -320,7 +320,7 @@ StereoCalib(const vector<string>& imagelist, Size boardSize, float squareSize, b
             for( j = 0; j < canvas.cols; j += 16 )
                 line(canvas, Point(j, 0), Point(j, canvas.rows), Scalar(0, 255, 0), 1, 8);
         imshow("rectified", canvas);
-        char c = (char)waitKey();
+        char c = waitChar();
         if( c == 27 || c == 'q' || c == 'Q' )
             break;
     }

samples/cpp/train_HOG.cpp

@@ -395,7 +395,7 @@ void test_it( const Size & size )
         draw_locations( draw, locations, trained );
 
         imshow( "Video", draw );
-        key = (char)waitKey( 10 );
+        key = waitChar( 10 );
         if( 27 == key )
             end_of_process = true;
     }

samples/cpp/tutorial_code/ImgProc/Pyramids.cpp

@@ -45,26 +45,22 @@ int main( void )
   //![infinite_loop]
   for(;;)
   {
-    int c;
+    char c = waitChar(0);
-    c = 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]
+    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' )
+    //![pyrup]
-      {
-        //![pyrdown]
-        pyrDown( tmp, dst, Size( tmp.cols/2, tmp.rows/2 ) );
     //![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/Smoothing.cpp

@@ -95,7 +95,7 @@ int display_caption( const char* caption )
            FONT_HERSHEY_COMPLEX, 1, Scalar(255, 255, 255) );
 
   imshow( window_name, dst );
-  int c = waitKey( DELAY_CAPTION );
+  char c = waitChar( DELAY_CAPTION );
   if( c >= 0 ) { return -1; }
   return 0;
 }
@@ -106,7 +106,7 @@ int display_caption( const char* caption )
 int display_dst( int delay )
 {
   imshow( window_name, dst );
-  int c = waitKey ( delay );
+  char c = waitChar( delay );
   if( c >= 0 ) { return -1; }
   return 0;
 }

samples/cpp/tutorial_code/ImgProc/Threshold.cpp

@@ -60,9 +60,8 @@ int main( int, char** argv )
   /// Wait until user finishes program
   for(;;)
     {
-      int c;
+      char c = waitChar( 20 );
-      c = waitKey( 20 );
+      if( c == 27 )
-      if( (char)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(waitChar(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 = waitChar(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 = waitChar( 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);
+         char c = waitChar(500);
-
+         if( c == 27 )
-         if( (char)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 = waitChar(500);
          /// Press 'ESC' to exit the program
-         if( (char)c == 27 )
+         if( c == 27 )
            { break; }
 
          //![update_kernel]

samples/cpp/tutorial_code/calib3d/camera_calibration/camera_calibration.cpp

@@ -393,7 +393,7 @@ int main(int argc, char* argv[])
         //------------------------------ Show image and check for input commands -------------------
         //! [await_input]
         imshow("Image View", view);
-        char key = (char)waitKey(s.inputCapture.isOpened() ? 50 : s.delay);
+        char key = waitChar(s.inputCapture.isOpened() ? 50 : s.delay);
 
         if( key  == ESC_KEY )
             break;
@@ -438,7 +438,7 @@ int main(int argc, char* argv[])
                 continue;
             remap(view, rview, map1, map2, INTER_LINEAR);
             imshow("Image View", rview);
-            char c = (char)waitKey();
+            char c = waitChar();
             if( c  == ESC_KEY || c == 'q' || c == 'Q' )
                 break;
         }

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) && waitChar(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(cv::waitChar(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);
+        char c = waitChar(10);
-        if( (char)c == 27 ) { break; } // escape
+        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);
+        char c = waitChar(10);
-        if( (char)c == 27 ) { break; }
+        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 = waitChar(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 = waitChar( 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 = waitChar( 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 = waitChar(delay);
         if (c == 27) break;
     }
 

samples/cpp/videostab.cpp

@@ -58,7 +58,7 @@ void run()
         if (!quietMode)
         {
             imshow("stabilizedFrame", stabilizedFrame);
-            char key = static_cast<char>(waitKey(3));
+            char key = waitChar(3);
             if (key == 27) { cout << endl; break; }
         }
     }

samples/cpp/watershed.cpp

@@ -74,19 +74,19 @@ int main( int argc, char** argv )
 
     for(;;)
     {
-        int c = waitKey(0);
+        char c = waitChar(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;

samples/gpu/alpha_comp.cpp

@@ -50,7 +50,7 @@ int main()
 
         imshow("Result", d_res);
 
-        char key = static_cast<char>(waitKey());
+        char key = waitChar();
 
         if (key == 27)
             break;

samples/gpu/bgfg_segm.cpp

@@ -161,7 +161,7 @@ int main(int argc, const char** argv)
         if (!bgimg.empty())
             imshow("mean background image", bgimg);
 
-        int key = waitKey(30);
+        char key = waitChar(30);
         if (key == 27)
             break;
     }

samples/gpu/cascadeclassifier.cpp

@@ -279,7 +279,7 @@ int main(int argc, const char *argv[])
         displayState(frameDisp, helpScreen, useGPU, findLargestObject, filterRects, fps);
         imshow("result", frameDisp);
 
-        char key = (char)waitKey(5);
+        char key = waitChar(5);
         if (key == 27)
         {
             break;

samples/gpu/cascadeclassifier_nvidia_api.cpp

@@ -348,7 +348,7 @@ int main(int argc, const char** argv)
         imshow(wndTitle, frameDisp);
 
         //handle input
-        switch (cv::waitKey(3))
+        switch (cv::waitChar(3))
         {
         case ' ':
             bUseGPU = !bUseGPU;

samples/gpu/farneback_optical_flow.cpp

@@ -125,7 +125,7 @@ int main(int argc, char **argv)
 
         imshow("flow", image);
 
-        char ch = (char)waitKey(3);
+        char ch = waitChar(3);
         if (ch == 27)
             running = false;
         else if (ch == 'm' || ch == 'M')

samples/gpu/morphology.cpp

@@ -81,7 +81,7 @@ int App::run()
         OpenClose();
         ErodeDilate();
 
-        char c = (char) waitKey();
+        char c = waitChar();
 
         switch (c)
         {

samples/gpu/opengl.cpp

@@ -105,8 +105,8 @@ int main(int argc, char* argv[])
     for (;;)
     {
         updateWindow("OpenGL");
-        int key = waitKey(40);
+        char key = waitChar(40);
-        if ((key & 0xff) == 27)
+        if (key == 27)
             break;
     }
 

samples/python/camshift.py

@@ -110,10 +110,10 @@ class App(object):
 
             cv2.imshow('camshift', vis)
 
-            ch = 0xFF & cv2.waitKey(5)
+            ch = cv2.waitChar(5)
             if ch == 27:
                 break
-            if ch == ord('b'):
+            if ch == 'b':
                 self.show_backproj = not self.show_backproj
         cv2.destroyAllWindows()
 

samples/python/coherence.py

@@ -77,8 +77,8 @@ if __name__ == '__main__':
     cv2.imshow('src', src)
     update()
     while True:
-        ch = 0xFF & cv2.waitKey()
+        ch = cv2.waitChar()
-        if ch == ord(' '):
+        if ch == ' ':
             update()
         if ch == 27:
             break

samples/python/color_histogram.py

@@ -56,7 +56,7 @@ if __name__ == '__main__':
         vis = hsv_map*h[:,:,np.newaxis] / 255.0
         cv2.imshow('hist', vis)
 
-        ch = 0xFF & cv2.waitKey(1)
+        ch = cv2.waitChar(1)
         if ch == 27:
             break
     cv2.destroyAllWindows()

samples/python/contours.py

@@ -66,5 +66,5 @@ if __name__ == '__main__':
     update(3)
     cv2.createTrackbar( "levels+3", "contours", 3, 7, update )
     cv2.imshow('image', img)
-    0xFF & cv2.waitKey()
+    cv2.waitKey()
     cv2.destroyAllWindows()

samples/python/deconvolution.py

@@ -122,9 +122,9 @@ if __name__ == '__main__':
     update(None)
 
     while True:
-        ch = cv2.waitKey() & 0xFF
+        ch = cv2.waitChar()
         if ch == 27:
             break
-        if ch == ord(' '):
+        if ch == ' ':
             defocus = not defocus
             update(None)

samples/python/digits_video.py

@@ -92,7 +92,7 @@ def main():
 
         cv2.imshow('frame', frame)
         cv2.imshow('bin', bin)
-        ch = cv2.waitKey(1) & 0xFF
+        ch = cv2.waitChar(1)
         if ch == 27:
             break
 

samples/python/distrans.py

@@ -59,10 +59,10 @@ if __name__ == '__main__':
 
 
     while True:
-        ch = 0xFF & cv2.waitKey(50)
+        ch = cv2.waitChar(50)
         if ch == 27:
             break
-        if ch == ord('v'):
+        if ch == 'v':
             voronoi = not voronoi
             print('showing', ['distance', 'voronoi'][voronoi])
             update()

samples/python/edge.py

@@ -49,7 +49,7 @@ if __name__ == '__main__':
         vis = np.uint8(vis/2.)
         vis[edge != 0] = (0, 255, 0)
         cv2.imshow('edge', vis)
-        ch = cv2.waitKey(5) & 0xFF
+        ch = cv2.waitChar(5)
         if ch == 27:
             break
     cv2.destroyAllWindows()

samples/python/facedetect.py

@@ -68,6 +68,6 @@ if __name__ == '__main__':
         draw_str(vis, (20, 20), 'time: %.1f ms' % (dt*1000))
         cv2.imshow('facedetect', vis)
 
-        if 0xFF & cv2.waitKey(5) == 27:
+        if cv2.waitChar(5) == 27:
             break
     cv2.destroyAllWindows()

samples/python/feature_homography.py

@@ -80,8 +80,8 @@ class App:
 
             self.rect_sel.draw(vis)
             cv2.imshow('plane', vis)
-            ch = cv2.waitKey(1)
+            ch = cv2.waitChar(1)
-            if ch == ord(' '):
+            if ch == ' ':
                 self.paused = not self.paused
             if ch == 27:
                 break

samples/python/fitline.py

@@ -88,8 +88,8 @@ if __name__ == '__main__':
     cv2.createTrackbar('outlier %', 'fit line', 30, 100, update)
     while True:
         update()
-        ch = cv2.waitKey(0) & 0xFF
+        ch = cv2.waitChar(0)
-        if ch == ord('f'):
+        if ch == 'f':
             if PY3:
                 cur_func_name = next(dist_func_names)
             else:

samples/python/floodfill.py

@@ -66,14 +66,14 @@ if __name__ == '__main__':
     cv2.createTrackbar('hi', 'floodfill', 20, 255, update)
 
     while True:
-        ch = 0xFF & cv2.waitKey()
+        ch = cv2.waitChar()
         if ch == 27:
             break
-        if ch == ord('f'):
+        if ch == 'f':
             fixed_range = not fixed_range
             print('using %s range' % ('floating', 'fixed')[fixed_range])
             update()
-        if ch == ord('c'):
+        if ch == 'c':
             connectivity = 12-connectivity
             print('connectivity =', connectivity)
             update()

samples/python/gaussian_mix.py

@@ -63,7 +63,7 @@ if __name__ == '__main__':
             draw_gaussain(img, m, cov, (0, 0, 255))
 
         cv2.imshow('gaussian mixture', img)
-        ch = 0xFF & cv2.waitKey(0)
+        ch = cv2.waitChar(0)
         if ch == 27:
             break
     cv2.destroyAllWindows()

samples/python/grabcut.py

@@ -129,27 +129,27 @@ if __name__ == '__main__':
 
         cv2.imshow('output',output)
         cv2.imshow('input',img)
-        k = 0xFF & cv2.waitKey(1)
+        k = cv2.waitChar(1)
 
         # key bindings
         if k == 27:         # esc to exit
             break
-        elif k == ord('0'): # BG drawing
+        elif k == '0': # BG drawing
             print(" mark background regions with left mouse button \n")
             value = DRAW_BG
-        elif k == ord('1'): # FG drawing
+        elif k == '1': # FG drawing
             print(" mark foreground regions with left mouse button \n")
             value = DRAW_FG
-        elif k == ord('2'): # PR_BG drawing
+        elif k == '2': # PR_BG drawing
             value = DRAW_PR_BG
-        elif k == ord('3'): # PR_FG drawing
+        elif k == '3': # PR_FG drawing
             value = DRAW_PR_FG
-        elif k == ord('s'): # save image
+        elif k == 's': # save image
             bar = np.zeros((img.shape[0],5,3),np.uint8)
             res = np.hstack((img2,bar,img,bar,output))
             cv2.imwrite('grabcut_output.png',res)
             print(" Result saved as image \n")
-        elif k == ord('r'): # reset everything
+        elif k == 'r': # reset everything
             print("resetting \n")
             rect = (0,0,1,1)
             drawing = False
@@ -160,7 +160,7 @@ if __name__ == '__main__':
             img = img2.copy()
             mask = np.zeros(img.shape[:2],dtype = np.uint8) # mask initialized to PR_BG
             output = np.zeros(img.shape,np.uint8)           # output image to be shown
-        elif k == ord('n'): # segment the image
+        elif k == 'n': # segment the image
             print(""" For finer touchups, mark foreground and background after pressing keys 0-3
             and again press 'n' \n""")
             if (rect_or_mask == 0):         # grabcut with rect

samples/python/hist.py

@@ -84,29 +84,29 @@ if __name__ == '__main__':
 
     cv2.imshow('image',im)
     while True:
-        k = cv2.waitKey(0)&0xFF
+        k = cv2.waitChar(0)
-        if k == ord('a'):
+        if k == 'a':
             curve = hist_curve(im)
             cv2.imshow('histogram',curve)
             cv2.imshow('image',im)
             print('a')
-        elif k == ord('b'):
+        elif k == 'b':
             print('b')
             lines = hist_lines(im)
             cv2.imshow('histogram',lines)
             cv2.imshow('image',gray)
-        elif k == ord('c'):
+        elif k == 'c':
             print('c')
             equ = cv2.equalizeHist(gray)
             lines = hist_lines(equ)
             cv2.imshow('histogram',lines)
             cv2.imshow('image',equ)
-        elif k == ord('d'):
+        elif k == 'd':
             print('d')
             curve = hist_curve(gray)
             cv2.imshow('histogram',curve)
             cv2.imshow('image',gray)
-        elif k == ord('e'):
+        elif k == 'e':
             print('e')
             norm = cv2.normalize(gray, gray, alpha = 0,beta = 255,norm_type = cv2.NORM_MINMAX)
             lines = hist_lines(norm)

samples/python/inpaint.py

@@ -41,13 +41,13 @@ if __name__ == '__main__':
     sketch = Sketcher('img', [img_mark, mark], lambda : ((255, 255, 255), 255))
 
     while True:
-        ch = 0xFF & cv2.waitKey()
+        ch = cv2.waitChar()
         if ch == 27:
             break
-        if ch == ord(' '):
+        if ch == ' ':
             res = cv2.inpaint(img_mark, mark, 3, cv2.INPAINT_TELEA)
             cv2.imshow('inpaint', res)
-        if ch == ord('r'):
+        if ch == 'r':
             img_mark[:] = img
             mark[:] = 0
             sketch.show()

samples/python/kalman.py

@@ -86,11 +86,11 @@ if __name__ == "__main__":
 
             cv2.imshow("Kalman", img)
 
-            code = cv2.waitKey(100)
+            code = cv2.waitChar(100)
             if code != -1:
                 break
 
-        if (code % 0x100) in [27, ord('q'), ord('Q')]:
+        if code in [27, 'q', 'Q']:
             break
 
     cv2.destroyWindow("Kalman")

samples/python/kmeans.py

@@ -44,7 +44,7 @@ if __name__ == '__main__':
             cv2.circle(img, (x, y), 1, c, -1)
 
         cv2.imshow('gaussian mixture', img)
-        ch = 0xFF & cv2.waitKey(0)
+        ch = cv2.waitChar(0)
         if ch == 27:
             break
     cv2.destroyAllWindows()

samples/python/lappyr.py

@@ -70,5 +70,5 @@ if __name__ == '__main__':
 
         cv2.imshow('laplacian pyramid filter', res)
 
-        if cv2.waitKey(1) & 0xFF == 27:
+        if cv2.waitChar(1) == 27:
             break

samples/python/lk_homography.py

@@ -90,17 +90,17 @@ class App:
 
             cv2.imshow('lk_homography', vis)
 
-            ch = 0xFF & cv2.waitKey(1)
+            ch = cv2.waitChar(1)
             if ch == 27:
                 break
-            if ch == ord(' '):
+            if ch == ' ':
                 self.frame0 = frame.copy()
                 self.p0 = cv2.goodFeaturesToTrack(frame_gray, **feature_params)
                 if self.p0 is not None:
                     self.p1 = self.p0
                     self.gray0 = frame_gray
                     self.gray1 = frame_gray
-            if ch == ord('r'):
+            if ch == 'r':
                 self.use_ransac = not self.use_ransac
 
 

samples/python/lk_track.py

@@ -85,7 +85,7 @@ class App:
             self.prev_gray = frame_gray
             cv2.imshow('lk_track', vis)
 
-            ch = 0xFF & cv2.waitKey(1)
+            ch = cv2.waitChar(1)
             if ch == 27:
                 break
 

samples/python/morphology.py

@@ -79,15 +79,15 @@ if __name__ == '__main__':
     cv2.createTrackbar('iters', 'morphology', 1, 10, update)
     update()
     while True:
-        ch = 0xFF & cv2.waitKey()
+        ch = cv2.waitChar()
         if ch == 27:
             break
-        if ch == ord('1'):
+        if ch == '1':
             if PY3:
                 cur_mode = next(modes)
             else:
                 cur_mode = modes.next()
-        if ch == ord('2'):
+        if ch == '2':
             if PY3:
                 cur_str_mode = next(str_modes)
             else:

samples/python/mosse.py

@@ -176,12 +176,12 @@ class App:
             self.rect_sel.draw(vis)
 
             cv2.imshow('frame', vis)
-            ch = cv2.waitKey(10) & 0xFF
+            ch = cv2.waitChar(10)
             if ch == 27:
                 break
-            if ch == ord(' '):
+            if ch == ' ':
                 self.paused = not self.paused
-            if ch == ord('c'):
+            if ch == 'c':
                 self.trackers = []
 
 

samples/python/mouse_and_match.py

@@ -78,6 +78,6 @@ if __name__ == '__main__':
             drag_start = None
             gray=cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
             cv2.imshow("gray",gray)
-            if (cv2.waitKey() & 255) == 27:
+            if cv2.waitChar() == 27:
                 break
     cv2.destroyAllWindows()

samples/python/mser.py

@@ -37,6 +37,6 @@ if __name__ == '__main__':
         cv2.polylines(vis, hulls, 1, (0, 255, 0))
 
         cv2.imshow('img', vis)
-        if 0xFF & cv2.waitKey(5) == 27:
+        if cv2.waitChar(5) == 27:
             break
     cv2.destroyAllWindows()

samples/python/opt_flow.py

@@ -83,13 +83,13 @@ if __name__ == '__main__':
             cur_glitch = warp_flow(cur_glitch, flow)
             cv2.imshow('glitch', cur_glitch)
 
-        ch = 0xFF & cv2.waitKey(5)
+        ch = cv2.waitChar(5)
         if ch == 27:
             break
-        if ch == ord('1'):
+        if ch == '1':
             show_hsv = not show_hsv
             print('HSV flow visualization is', ['off', 'on'][show_hsv])
-        if ch == ord('2'):
+        if ch == '2':
             show_glitch = not show_glitch
             if show_glitch:
                 cur_glitch = img.copy()

samples/python/peopledetect.py

@@ -65,7 +65,7 @@ if __name__ == '__main__':
         draw_detections(img, found_filtered, 3)
         print('%d (%d) found' % (len(found_filtered), len(found)))
         cv2.imshow('img', img)
-        ch = 0xFF & cv2.waitKey()
+        ch = cv2.waitChar()
         if ch == 27:
             break
     cv2.destroyAllWindows()

samples/python/plane_ar.py

@@ -75,10 +75,10 @@ class App:
 
             self.rect_sel.draw(vis)
             cv2.imshow('plane', vis)
-            ch = cv2.waitKey(1) & 0xFF
+            ch = cv2.waitChar(1)
-            if ch == ord(' '):
+            if ch == ' ':
                 self.paused = not self.paused
-            if ch == ord('c'):
+            if ch == 'c':
                 self.tracker.clear()
             if ch == 27:
                 break

samples/python/plane_tracker.py

@@ -170,10 +170,10 @@ class App:
 
             self.rect_sel.draw(vis)
             cv2.imshow('plane', vis)
-            ch = cv2.waitKey(1) & 0xFF
+            ch = cv2.waitChar(1)
-            if ch == ord(' '):
+            if ch == ' ':
                 self.paused = not self.paused
-            if ch == ord('c'):
+            if ch == 'c':
                 self.tracker.clear()
             if ch == 27:
                 break

samples/python/squares.py

@@ -49,7 +49,7 @@ if __name__ == '__main__':
         squares = find_squares(img)
         cv2.drawContours( img, squares, -1, (0, 255, 0), 3 )
         cv2.imshow('squares', img)
-        ch = 0xFF & cv2.waitKey()
+        ch = cv2.waitChar()
         if ch == 27:
             break
     cv2.destroyAllWindows()

samples/python/tst_scene_render.py

@@ -108,7 +108,7 @@ if __name__ == '__main__':
         img = render.getNextFrame()
         cv2.imshow('img', img)
 
-        ch = 0xFF & cv2.waitKey(3)
+        ch = cv2.waitChar(3)
         if  ch == 27:
             break
     #import os

samples/python/turing.py

@@ -69,6 +69,6 @@ if __name__ == '__main__':
         vis = a.copy()
         draw_str(vis, (20, 20), 'frame %d' % frame_i)
         cv2.imshow('a', vis)
-        if 0xFF & cv2.waitKey(5) == 27:
+        if cv2.waitChar(5) == 27:
             break
     cv2.destroyAllWindows()

samples/python/video.py

@@ -217,10 +217,10 @@ if __name__ == '__main__':
             ret, img = cap.read()
             imgs.append(img)
             cv2.imshow('capture %d' % i, img)
-        ch = 0xFF & cv2.waitKey(1)
+        ch = cv2.waitChar(1)
         if ch == 27:
             break
-        if ch == ord(' '):
+        if ch == ' ':
             for i, img in enumerate(imgs):
                 fn = '%s/shot_%d_%03d.bmp' % (shotdir, i, shot_idx)
                 cv2.imwrite(fn, img)

samples/python/video_threaded.py

@@ -81,8 +81,8 @@ if __name__ == '__main__':
             else:
                 task = DummyTask(process_frame(frame, t))
             pending.append(task)
-        ch = 0xFF & cv2.waitKey(1)
+        ch = cv2.waitChar(1)
-        if ch == ord(' '):
+        if ch == ' ':
             threaded_mode = not threaded_mode
         if ch == 27:
             break

samples/python/video_v4l2.py

@@ -58,10 +58,10 @@ while True:
     cv2.putText(img, "FPS: {}".format(fps), (15, 80), font, 1.0, color)
     cv2.imshow("Video", img)
 
-    k = 0xFF & cv2.waitKey(1)
+    k = cv2.waitChar(1)
 
     if k == 27:
         break
-    elif k == ord("g"):
+    elif k == 'g':
         convert_rgb = not convert_rgb
         cap.set(cv2.CAP_PROP_CONVERT_RGB, convert_rgb)

samples/python/watershed.py

@@ -56,19 +56,19 @@ class App:
 
     def run(self):
         while cv2.getWindowProperty('img', 0) != -1 or cv2.getWindowProperty('watershed', 0) != -1:
-            ch = 0xFF & cv2.waitKey(50)
+            ch = cv2.waitChar(50)
             if ch == 27:
                 break
-            if ch >= ord('1') and ch <= ord('7'):
+            if ch >= '1' and ch <= '7':
-                self.cur_marker = ch - ord('0')
+                self.cur_marker = ch - '0'
                 print('marker: ', self.cur_marker)
-            if ch == ord(' ') or (self.sketch.dirty and self.auto_update):
+            if ch == ' ' or (self.sketch.dirty and self.auto_update):
                 self.watershed()
                 self.sketch.dirty = False
-            if ch in [ord('a'), ord('A')]:
+            if ch in ['a', 'A']:
                 self.auto_update = not self.auto_update
                 print('auto_update if', ['off', 'on'][self.auto_update])
-            if ch in [ord('r'), ord('R')]:
+            if ch in ['r', 'R']:
                 self.markers[:] = 0
                 self.markers_vis[:] = self.img
                 self.sketch.show()

samples/tapi/bgfg_segm.cpp

@@ -105,7 +105,7 @@ int main(int argc, const char** argv)
         imshow("foreground mask", fgmask);
         imshow("foreground image", fgimg);
 
-        char key = (char)waitKey(30);
+        char key = waitChar(30);
 
         switch (key)
         {