Add Java and Python code for cascade classifier and HDR tutorials.

doc/py_tutorials/py_objdetect/py_face_detection/py_face_detection.markdown

@@ -126,9 +126,9 @@ Result looks like below:
 Additional Resources
 --------------------
 
--#  Video Lecture on [Face Detection and Tracking](http://www.youtube.com/watch?v=WfdYYNamHZ8)
-2.  An interesting interview regarding Face Detection by [Adam
-    Harvey](http://www.makematics.com/research/viola-jones/)
+-#  Video Lecture on [Face Detection and Tracking](https://www.youtube.com/watch?v=WfdYYNamHZ8)
+-#  An interesting interview regarding Face Detection by [Adam
+    Harvey](https://web.archive.org/web/20171204220159/http://www.makematics.com/research/viola-jones/)
 
 Exercises
 ---------

doc/py_tutorials/py_photo/py_hdr/py_hdr.markdown

@@ -27,7 +27,7 @@ merged, it has to be converted back to 8-bit to view it on usual displays. This
 tonemapping. Additional complexities arise when objects of the scene or camera move between shots,
 since images with different exposures should be registered and aligned.
 
-In this tutorial we show 2 algorithms (Debvec, Robertson) to generate and display HDR image from an
+In this tutorial we show 2 algorithms (Debevec, Robertson) to generate and display HDR image from an
 exposure sequence, and demonstrate an alternative approach called exposure fusion (Mertens), that
 produces low dynamic range image and does not need the exposure times data.
 Furthermore, we estimate the camera response function (CRF) which is of great value for many computer
@@ -65,14 +65,14 @@ exposure_times = np.array([15.0, 2.5, 0.25, 0.0333], dtype=np.float32)
 ### 2. Merge exposures into HDR image
 
 In this stage we merge the exposure sequence into one HDR image, showing 2 possibilities
-which we have in OpenCV. The first method is Debvec and the second one is Robertson.
+which we have in OpenCV. The first method is Debevec and the second one is Robertson.
 Notice that the HDR image is of type float32, and not uint8, as it contains the
 full dynamic range of all exposure images.
 
 @code{.py}
 # Merge exposures to HDR image
-merge_debvec = cv.createMergeDebevec()
-hdr_debvec = merge_debvec.process(img_list, times=exposure_times.copy())
+merge_debevec = cv.createMergeDebevec()
+hdr_debevec = merge_debevec.process(img_list, times=exposure_times.copy())
 merge_robertson = cv.createMergeRobertson()
 hdr_robertson = merge_robertson.process(img_list, times=exposure_times.copy())
 @endcode
@@ -86,7 +86,7 @@ we will later have to clip the data in order to avoid overflow.
 @code{.py}
 # Tonemap HDR image
 tonemap1 = cv.createTonemapDurand(gamma=2.2)
-res_debvec = tonemap1.process(hdr_debvec.copy())
+res_debevec = tonemap1.process(hdr_debevec.copy())
 tonemap2 = cv.createTonemapDurand(gamma=1.3)
 res_robertson = tonemap2.process(hdr_robertson.copy())
 @endcode
@@ -111,11 +111,11 @@ integers in the range of [0..255].
 
 @code{.py}
 # Convert datatype to 8-bit and save
-res_debvec_8bit = np.clip(res_debvec*255, 0, 255).astype('uint8')
+res_debevec_8bit = np.clip(res_debevec*255, 0, 255).astype('uint8')
 res_robertson_8bit = np.clip(res_robertson*255, 0, 255).astype('uint8')
 res_mertens_8bit = np.clip(res_mertens*255, 0, 255).astype('uint8')
 
-cv.imwrite("ldr_debvec.jpg", res_debvec_8bit)
+cv.imwrite("ldr_debevec.jpg", res_debevec_8bit)
 cv.imwrite("ldr_robertson.jpg", res_robertson_8bit)
 cv.imwrite("fusion_mertens.jpg", res_mertens_8bit)
 @endcode
@@ -127,9 +127,9 @@ You can see the different results but consider that each algorithm have addition
 extra parameters that you should fit to get your desired outcome. Best practice is
 to try the different methods and see which one performs best for your scene.
 
-### Debvec:
+### Debevec:
 
-![image](images/ldr_debvec.jpg)
+![image](images/ldr_debevec.jpg)
 
 ### Robertson:
 
@@ -150,9 +150,9 @@ function and use it for the HDR merge.
 
 @code{.py}
 # Estimate camera response function (CRF)
-cal_debvec = cv.createCalibrateDebevec()
-crf_debvec = cal_debvec.process(img_list, times=exposure_times)
-hdr_debvec = merge_debvec.process(img_list, times=exposure_times.copy(), response=crf_debvec.copy())
+cal_debevec = cv.createCalibrateDebevec()
+crf_debevec = cal_debevec.process(img_list, times=exposure_times)
+hdr_debevec = merge_debevec.process(img_list, times=exposure_times.copy(), response=crf_debevec.copy())
 cal_robertson = cv.createCalibrateRobertson()
 crf_robertson = cal_robertson.process(img_list, times=exposure_times)
 hdr_robertson = merge_robertson.process(img_list, times=exposure_times.copy(), response=crf_robertson.copy())
@@ -166,12 +166,12 @@ For this sequence we got the following estimation:
 Additional Resources
 --------------------
 
-1. Paul E Debevec and Jitendra Malik. Recovering high dynamic range radiance maps from photographs. In ACM SIGGRAPH 2008 classes, page 31. ACM, 2008.
-2. Mark A Robertson, Sean Borman, and Robert L Stevenson. Dynamic range improvement through multiple exposures. In Image Processing, 1999. ICIP 99. Proceedings. 1999 International Conference on, volume 3, pages 159–163. IEEE, 1999.
-3. Tom Mertens, Jan Kautz, and Frank Van Reeth. Exposure fusion. In Computer Graphics and Applications, 2007. PG'07. 15th Pacific Conference on, pages 382–390. IEEE, 2007.
+1. Paul E Debevec and Jitendra Malik. Recovering high dynamic range radiance maps from photographs. In ACM SIGGRAPH 2008 classes, page 31. ACM, 2008. @cite DM97
+2. Mark A Robertson, Sean Borman, and Robert L Stevenson. Dynamic range improvement through multiple exposures. In Image Processing, 1999. ICIP 99. Proceedings. 1999 International Conference on, volume 3, pages 159–163. IEEE, 1999. @cite RB99
+3. Tom Mertens, Jan Kautz, and Frank Van Reeth. Exposure fusion. In Computer Graphics and Applications, 2007. PG'07. 15th Pacific Conference on, pages 382–390. IEEE, 2007. @cite MK07
 4. Images from [Wikipedia-HDR](https://en.wikipedia.org/wiki/High-dynamic-range_imaging)
 
 Exercises
 ---------
-1. Try all tonemap algorithms: [Drago](http://docs.opencv.org/master/da/d53/classcv_1_1TonemapDrago.html), [Durand](http://docs.opencv.org/master/da/d3d/classcv_1_1TonemapDurand.html), [Mantiuk](http://docs.opencv.org/master/de/d76/classcv_1_1TonemapMantiuk.html) and [Reinhard](http://docs.opencv.org/master/d0/dec/classcv_1_1TonemapReinhard.html).
-2. Try changing the parameters in the HDR calibration and tonemap methods.
+1. Try all tonemap algorithms: cv::TonemapDrago, cv::TonemapDurand, cv::TonemapMantiuk and cv::TonemapReinhard
+2. Try changing the parameters in the HDR calibration and tonemap methods.
\ No newline at end of file

doc/tutorials/objdetect/cascade_classifier/cascade_classifier.markdown

@@ -17,9 +17,23 @@ Theory
 Code
 ----
 
+@add_toggle_cpp
 This tutorial code's is shown lines below. You can also download it from
 [here](https://github.com/opencv/opencv/tree/3.4/samples/cpp/tutorial_code/objectDetection/objectDetection.cpp)
 @include samples/cpp/tutorial_code/objectDetection/objectDetection.cpp
+@end_toggle
+
+@add_toggle_java
+This tutorial code's is shown lines below. You can also download it from
+[here](https://github.com/opencv/opencv/tree/3.4/samples/java/tutorial_code/objectDetection/cascade_classifier/ObjectDetectionDemo.java)
+@include samples/java/tutorial_code/objectDetection/cascade_classifier/ObjectDetectionDemo.java
+@end_toggle
+
+@add_toggle_python
+This tutorial code's is shown lines below. You can also download it from
+[here](https://github.com/opencv/opencv/tree/3.4/samples/python/tutorial_code/objectDetection/cascade_classifier/objectDetection.py)
+@include samples/python/tutorial_code/objectDetection/cascade_classifier/objectDetection.py
+@end_toggle
 
 Explanation
 -----------
@@ -40,3 +54,13 @@ Result
     detection. For the eyes we keep using the file used in the tutorial.
 
     ![](images/Cascade_Classifier_Tutorial_Result_LBP.jpg)
+
+Additional Resources
+--------------------
+
+-#  Paul Viola and Michael J. Jones. Robust real-time face detection. International Journal of Computer Vision, 57(2):137–154, 2004. @cite Viola04
+-#  Rainer Lienhart and Jochen Maydt. An extended set of haar-like features for rapid object detection. In Image Processing. 2002. Proceedings. 2002 International Conference on, volume 1, pages I–900. IEEE, 2002. @cite Lienhart02
+-#  Video Lecture on [Face Detection and Tracking](https://www.youtube.com/watch?v=WfdYYNamHZ8)
+-#  An interesting interview regarding Face Detection by [Adam
+    Harvey](https://web.archive.org/web/20171204220159/http://www.makematics.com/research/viola-jones/)
+-#  [OpenCV Face Detection: Visualized](https://vimeo.com/12774628) on Vimeo by Adam Harvey

doc/tutorials/objdetect/table_of_content_objdetect.markdown

@@ -5,6 +5,8 @@ Ever wondered how your digital camera detects peoples and faces? Look here to fi
 
 -   @subpage tutorial_cascade_classifier
 
+    *Languages:* C++, Java, Python
+
     *Compatibility:* \> OpenCV 2.0
 
     *Author:* Ana Huamán

doc/tutorials/photo/hdr_imaging/hdr_imaging.markdown

@@ -31,21 +31,51 @@ Exposure sequence
 Source Code
 -----------
 
-@include cpp/tutorial_code/photo/hdr_imaging/hdr_imaging.cpp
+@add_toggle_cpp
+This tutorial code's is shown lines below. You can also download it from
+[here](https://github.com/opencv/opencv/tree/3.4/samples/cpp/tutorial_code/photo/hdr_imaging/hdr_imaging.cpp)
+@include samples/cpp/tutorial_code/photo/hdr_imaging/hdr_imaging.cpp
+@end_toggle
+
+@add_toggle_java
+This tutorial code's is shown lines below. You can also download it from
+[here](https://github.com/opencv/opencv/tree/3.4/samples/java/tutorial_code/photo/hdr_imaging/HDRImagingDemo.java)
+@include samples/java/tutorial_code/photo/hdr_imaging/HDRImagingDemo.java
+@end_toggle
+
+@add_toggle_python
+This tutorial code's is shown lines below. You can also download it from
+[here](https://github.com/opencv/opencv/tree/3.4/samples/python/tutorial_code/photo/hdr_imaging/hdr_imaging.py)
+@include samples/python/tutorial_code/photo/hdr_imaging/hdr_imaging.py
+@end_toggle
+
+Sample images
+-------------
+
+Data directory that contains images, exposure times and `list.txt` file can be downloaded from
+[here](https://github.com/opencv/opencv_extra/tree/3.4/testdata/cv/hdr/exposures).
 
 Explanation
 -----------
 
--#  **Load images and exposure times**
-    @code{.cpp}
-    vector<Mat> images;
-    vector<float> times;
-    loadExposureSeq(argv[1], images, times);
-    @endcode
-    Firstly we load input images and exposure times from user-defined folder. The folder should
-    contain images and *list.txt* - file that contains file names and inverse exposure times.
+-   **Load images and exposure times**
+
+@add_toggle_cpp
+@snippet samples/cpp/tutorial_code/photo/hdr_imaging/hdr_imaging.cpp Load images and exposure times
+@end_toggle
+
+@add_toggle_java
+@snippet samples/java/tutorial_code/photo/hdr_imaging/HDRImagingDemo.java Load images and exposure times
+@end_toggle
+
+@add_toggle_python
+@snippet samples/python/tutorial_code/photo/hdr_imaging/hdr_imaging.py Load images and exposure times
+@end_toggle
+
+Firstly we load input images and exposure times from user-defined folder. The folder should
+contain images and *list.txt* - file that contains file names and inverse exposure times.
 
-    For our image sequence the list is following:
+For our image sequence the list is following:
     @code{.none}
     memorial00.png 0.03125
     memorial01.png 0.0625
@@ -53,53 +83,96 @@ Explanation
     memorial15.png 1024
     @endcode
 
--#  **Estimate camera response**
-    @code{.cpp}
-    Mat response;
-    Ptr<CalibrateDebevec> calibrate = createCalibrateDebevec();
-    calibrate->process(images, response, times);
-    @endcode
-    It is necessary to know camera response function (CRF) for a lot of HDR construction algorithms.
-    We use one of the calibration algorithms to estimate inverse CRF for all 256 pixel values.
-
--#  **Make HDR image**
-@code{.cpp}
-Mat hdr;
-Ptr<MergeDebevec> merge_debevec = createMergeDebevec();
-merge_debevec->process(images, hdr, times, response);
-@endcode
+-   **Estimate camera response**
+
+@add_toggle_cpp
+@snippet samples/cpp/tutorial_code/photo/hdr_imaging/hdr_imaging.cpp Estimate camera response
+@end_toggle
+
+@add_toggle_java
+@snippet samples/java/tutorial_code/photo/hdr_imaging/HDRImagingDemo.java Estimate camera response
+@end_toggle
+
+@add_toggle_python
+@snippet samples/python/tutorial_code/photo/hdr_imaging/hdr_imaging.py Estimate camera response
+@end_toggle
+
+It is necessary to know camera response function (CRF) for a lot of HDR construction algorithms.
+We use one of the calibration algorithms to estimate inverse CRF for all 256 pixel values.
+
+-   **Make HDR image**
+
+@add_toggle_cpp
+@snippet samples/cpp/tutorial_code/photo/hdr_imaging/hdr_imaging.cpp Make HDR image
+@end_toggle
+
+@add_toggle_java
+@snippet samples/java/tutorial_code/photo/hdr_imaging/HDRImagingDemo.java Make HDR image
+@end_toggle
+
+@add_toggle_python
+@snippet samples/python/tutorial_code/photo/hdr_imaging/hdr_imaging.py Make HDR image
+@end_toggle
+
 We use Debevec's weighting scheme to construct HDR image using response calculated in the previous
 item.
 
--#  **Tonemap HDR image**
-    @code{.cpp}
-    Mat ldr;
-    Ptr<TonemapDurand> tonemap = createTonemapDurand(2.2f);
-    tonemap->process(hdr, ldr);
-    @endcode
-    Since we want to see our results on common LDR display we have to map our HDR image to 8-bit range
-    preserving most details. It is the main goal of tonemapping methods. We use tonemapper with
-    bilateral filtering and set 2.2 as the value for gamma correction.
-
--#  **Perform exposure fusion**
-    @code{.cpp}
-    Mat fusion;
-    Ptr<MergeMertens> merge_mertens = createMergeMertens();
-    merge_mertens->process(images, fusion);
-    @endcode
-    There is an alternative way to merge our exposures in case when we don't need HDR image. This
-    process is called exposure fusion and produces LDR image that doesn't require gamma correction. It
-    also doesn't use exposure values of the photographs.
-
--#  **Write results**
-    @code{.cpp}
-    imwrite("fusion.png", fusion * 255);
-    imwrite("ldr.png", ldr * 255);
-    imwrite("hdr.hdr", hdr);
-    @endcode
-    Now it's time to look at the results. Note that HDR image can't be stored in one of common image
-    formats, so we save it to Radiance image (.hdr). Also all HDR imaging functions return results in
-    [0, 1] range so we should multiply result by 255.
+-   **Tonemap HDR image**
+
+@add_toggle_cpp
+@snippet samples/cpp/tutorial_code/photo/hdr_imaging/hdr_imaging.cpp Tonemap HDR image
+@end_toggle
+
+@add_toggle_java
+@snippet samples/java/tutorial_code/photo/hdr_imaging/HDRImagingDemo.java Tonemap HDR image
+@end_toggle
+
+@add_toggle_python
+@snippet samples/python/tutorial_code/photo/hdr_imaging/hdr_imaging.py Tonemap HDR image
+@end_toggle
+
+Since we want to see our results on common LDR display we have to map our HDR image to 8-bit range
+preserving most details. It is the main goal of tonemapping methods. We use tonemapper with
+bilateral filtering and set 2.2 as the value for gamma correction.
+
+-   **Perform exposure fusion**
+
+@add_toggle_cpp
+@snippet samples/cpp/tutorial_code/photo/hdr_imaging/hdr_imaging.cpp Perform exposure fusion
+@end_toggle
+
+@add_toggle_java
+@snippet samples/java/tutorial_code/photo/hdr_imaging/HDRImagingDemo.java Perform exposure fusion
+@end_toggle
+
+@add_toggle_python
+@snippet samples/python/tutorial_code/photo/hdr_imaging/hdr_imaging.py Perform exposure fusion
+@end_toggle
+
+There is an alternative way to merge our exposures in case when we don't need HDR image. This
+process is called exposure fusion and produces LDR image that doesn't require gamma correction. It
+also doesn't use exposure values of the photographs.
+
+-   **Write results**
+
+@add_toggle_cpp
+@snippet samples/cpp/tutorial_code/photo/hdr_imaging/hdr_imaging.cpp Write results
+@end_toggle
+
+@add_toggle_java
+@snippet samples/java/tutorial_code/photo/hdr_imaging/HDRImagingDemo.java Write results
+@end_toggle
+
+@add_toggle_python
+@snippet samples/python/tutorial_code/photo/hdr_imaging/hdr_imaging.py Write results
+@end_toggle
+
+Now it's time to look at the results. Note that HDR image can't be stored in one of common image
+formats, so we save it to Radiance image (.hdr). Also all HDR imaging functions return results in
+[0, 1] range so we should multiply result by 255.
+
+You can try other tonemap algorithms: cv::TonemapDrago, cv::TonemapDurand, cv::TonemapMantiuk and cv::TonemapReinhard
+You can also adjust the parameters in the HDR calibration and tonemap methods for your own photos.
 
 Results
 -------
@@ -111,3 +184,12 @@ Results
 ### Exposure fusion
 
 ![](images/fusion.png)
+
+Additional Resources
+--------------------
+
+1. Paul E Debevec and Jitendra Malik. Recovering high dynamic range radiance maps from photographs. In ACM SIGGRAPH 2008 classes, page 31. ACM, 2008. @cite DM97
+2. Mark A Robertson, Sean Borman, and Robert L Stevenson. Dynamic range improvement through multiple exposures. In Image Processing, 1999. ICIP 99. Proceedings. 1999 International Conference on, volume 3, pages 159–163. IEEE, 1999. @cite RB99
+3. Tom Mertens, Jan Kautz, and Frank Van Reeth. Exposure fusion. In Computer Graphics and Applications, 2007. PG'07. 15th Pacific Conference on, pages 382–390. IEEE, 2007. @cite MK07
+4. [Wikipedia-HDR](https://en.wikipedia.org/wiki/High-dynamic-range_imaging)
+5. [Recovering High Dynamic Range Radiance Maps from Photographs (webpage)](http://www.pauldebevec.com/Research/HDR/)

doc/tutorials/photo/table_of_content_photo.markdown

@@ -5,6 +5,8 @@ Use OpenCV for advanced photo processing.
 
 -   @subpage tutorial_hdr_imaging
 
+    *Languages:* C++, Java, Python
+
     *Compatibility:* \> OpenCV 3.0
 
     *Author:* Fedor Morozov

samples/cpp/tutorial_code/objectDetection/objectDetection.cpp

@@ -2,7 +2,7 @@
 #include "opencv2/highgui.hpp"
 #include "opencv2/imgproc.hpp"
 
-#include <stdio.h>
+#include <iostream>
 
 using namespace std;
 using namespace cv;
@@ -11,48 +11,63 @@ using namespace cv;
 void detectAndDisplay( Mat frame );
 
 /** Global variables */
-String face_cascade_name, eyes_cascade_name;
 CascadeClassifier face_cascade;
 CascadeClassifier eyes_cascade;
-String window_name = "Capture - Face detection";
 
 /** @function main */
 int main( int argc, const char** argv )
 {
     CommandLineParser parser(argc, argv,
-        "{help h||}"
-        "{face_cascade|../../data/haarcascades/haarcascade_frontalface_alt.xml|}"
-        "{eyes_cascade|../../data/haarcascades/haarcascade_eye_tree_eyeglasses.xml|}");
+                             "{help h||}"
+                             "{face_cascade|../../data/haarcascades/haarcascade_frontalface_alt.xml|Path to face cascade.}"
+                             "{eyes_cascade|../../data/haarcascades/haarcascade_eye_tree_eyeglasses.xml|Path to eyes cascade.}"
+                             "{camera|0|Camera device number.}");
 
     parser.about( "\nThis program demonstrates using the cv::CascadeClassifier class to detect objects (Face + eyes) in a video stream.\n"
                   "You can use Haar or LBP features.\n\n" );
     parser.printMessage();
 
-    face_cascade_name = parser.get<String>("face_cascade");
-    eyes_cascade_name = parser.get<String>("eyes_cascade");
-    VideoCapture capture;
-    Mat frame;
+    String face_cascade_name = parser.get<String>("face_cascade");
+    String eyes_cascade_name = parser.get<String>("eyes_cascade");
 
     //-- 1. Load the cascades
-    if( !face_cascade.load( face_cascade_name ) ){ printf("--(!)Error loading face cascade\n"); return -1; };
-    if( !eyes_cascade.load( eyes_cascade_name ) ){ printf("--(!)Error loading eyes cascade\n"); return -1; };
+    if( !face_cascade.load( face_cascade_name ) )
+    {
+        cout << "--(!)Error loading face cascade\n";
+        return -1;
+    };
+    if( !eyes_cascade.load( eyes_cascade_name ) )
+    {
+        cout << "--(!)Error loading eyes cascade\n";
+        return -1;
+    };
 
+    int camera_device = parser.get<int>("camera");
+    VideoCapture capture;
     //-- 2. Read the video stream
-    capture.open( 0 );
-    if ( ! capture.isOpened() ) { printf("--(!)Error opening video capture\n"); return -1; }
+    capture.open( camera_device );
+    if ( ! capture.isOpened() )
+    {
+        cout << "--(!)Error opening video capture\n";
+        return -1;
+    }
 
+    Mat frame;
     while ( capture.read(frame) )
     {
         if( frame.empty() )
         {
-            printf(" --(!) No captured frame -- Break!");
+            cout << "--(!) No captured frame -- Break!\n";
             break;
         }
 
         //-- 3. Apply the classifier to the frame
         detectAndDisplay( frame );
 
-        if( waitKey(10) == 27 ) { break; } // escape
+        if( waitKey(10) == 27 )
+        {
+            break; // escape
+        }
     }
     return 0;
 }
@@ -60,33 +75,33 @@ int main( int argc, const char** argv )
 /** @function detectAndDisplay */
 void detectAndDisplay( Mat frame )
 {
-    std::vector<Rect> faces;
     Mat frame_gray;
-
     cvtColor( frame, frame_gray, COLOR_BGR2GRAY );
     equalizeHist( frame_gray, frame_gray );
 
     //-- Detect faces
-    face_cascade.detectMultiScale( frame_gray, faces, 1.1, 2, 0|CASCADE_SCALE_IMAGE, Size(60, 60) );
+    std::vector<Rect> faces;
+    face_cascade.detectMultiScale( frame_gray, faces );
 
     for ( size_t i = 0; i < faces.size(); i++ )
     {
         Point center( faces[i].x + faces[i].width/2, faces[i].y + faces[i].height/2 );
-        ellipse( frame, center, Size( faces[i].width/2, faces[i].height/2 ), 0, 0, 360, Scalar( 255, 0, 255 ), 4, 8, 0 );
+        ellipse( frame, center, Size( faces[i].width/2, faces[i].height/2 ), 0, 0, 360, Scalar( 255, 0, 255 ), 4 );
 
         Mat faceROI = frame_gray( faces[i] );
-        std::vector<Rect> eyes;
 
         //-- In each face, detect eyes
-        eyes_cascade.detectMultiScale( faceROI, eyes, 1.1, 2, 0 |CASCADE_SCALE_IMAGE, Size(30, 30) );
+        std::vector<Rect> eyes;
+        eyes_cascade.detectMultiScale( faceROI, eyes );
 
         for ( size_t j = 0; j < eyes.size(); j++ )
         {
             Point eye_center( faces[i].x + eyes[j].x + eyes[j].width/2, faces[i].y + eyes[j].y + eyes[j].height/2 );
             int radius = cvRound( (eyes[j].width + eyes[j].height)*0.25 );
-            circle( frame, eye_center, radius, Scalar( 255, 0, 0 ), 4, 8, 0 );
+            circle( frame, eye_center, radius, Scalar( 255, 0, 0 ), 4 );
         }
     }
+
     //-- Show what you got
-    imshow( window_name, frame );
+    imshow( "Capture - Face detection", frame );
 }

samples/cpp/tutorial_code/photo/hdr_imaging/hdr_imaging.cpp

-#include <opencv2/photo.hpp>
+#include "opencv2/photo.hpp"
 #include "opencv2/imgcodecs.hpp"
-#include <opencv2/highgui.hpp>
+#include "opencv2/highgui.hpp"
+
 #include <vector>
 #include <iostream>
 #include <fstream>
@@ -10,38 +11,52 @@ using namespace std;
 
 void loadExposureSeq(String, vector<Mat>&, vector<float>&);
 
-int main(int, char**argv)
+int main(int argc, char**argv)
 {
+    CommandLineParser parser( argc, argv, "{@input | | Input directory that contains images and exposure times. }" );
+
+    //! [Load images and exposure times]
     vector<Mat> images;
     vector<float> times;
-    loadExposureSeq(argv[1], images, times);
+    loadExposureSeq(parser.get<String>( "@input" ), images, times);
+    //! [Load images and exposure times]
 
+    //! [Estimate camera response]
     Mat response;
     Ptr<CalibrateDebevec> calibrate = createCalibrateDebevec();
     calibrate->process(images, response, times);
+    //! [Estimate camera response]
 
+    //! [Make HDR image]
     Mat hdr;
     Ptr<MergeDebevec> merge_debevec = createMergeDebevec();
     merge_debevec->process(images, hdr, times, response);
+    //! [Make HDR image]
 
+    //! [Tonemap HDR image]
     Mat ldr;
     Ptr<TonemapDurand> tonemap = createTonemapDurand(2.2f);
     tonemap->process(hdr, ldr);
+    //! [Tonemap HDR image]
 
+    //! [Perform exposure fusion]
     Mat fusion;
     Ptr<MergeMertens> merge_mertens = createMergeMertens();
     merge_mertens->process(images, fusion);
+    //! [Perform exposure fusion]
 
+    //! [Write results]
     imwrite("fusion.png", fusion * 255);
     imwrite("ldr.png", ldr * 255);
     imwrite("hdr.hdr", hdr);
+    //! [Write results]
 
     return 0;
 }
 
 void loadExposureSeq(String path, vector<Mat>& images, vector<float>& times)
 {
-    path = path + std::string("/");
+    path = path + "/";
     ifstream list_file((path + "list.txt").c_str());
     string name;
     float val;

samples/java/tutorial_code/objectDetection/cascade_classifier/ObjectDetectionDemo.java

+import java.util.List;
+
+import org.opencv.core.Core;
+import org.opencv.core.Mat;
+import org.opencv.core.MatOfRect;
+import org.opencv.core.Point;
+import org.opencv.core.Rect;
+import org.opencv.core.Scalar;
+import org.opencv.core.Size;
+import org.opencv.highgui.HighGui;
+import org.opencv.imgproc.Imgproc;
+import org.opencv.objdetect.CascadeClassifier;
+import org.opencv.videoio.VideoCapture;
+
+class ObjectDetection {
+    public void detectAndDisplay(Mat frame, CascadeClassifier faceCascade, CascadeClassifier eyesCascade) {
+        Mat frameGray = new Mat();
+        Imgproc.cvtColor(frame, frameGray, Imgproc.COLOR_BGR2GRAY);
+        Imgproc.equalizeHist(frameGray, frameGray);
+
+        // -- Detect faces
+        MatOfRect faces = new MatOfRect();
+        faceCascade.detectMultiScale(frameGray, faces);
+
+        List<Rect> listOfFaces = faces.toList();
+        for (Rect face : listOfFaces) {
+            Point center = new Point(face.x + face.width / 2, face.y + face.height / 2);
+            Imgproc.ellipse(frame, center, new Size(face.width / 2, face.height / 2), 0, 0, 360,
+                    new Scalar(255, 0, 255));
+
+            Mat faceROI = frameGray.submat(face);
+
+            // -- In each face, detect eyes
+            MatOfRect eyes = new MatOfRect();
+            eyesCascade.detectMultiScale(faceROI, eyes);
+
+            List<Rect> listOfEyes = eyes.toList();
+            for (Rect eye : listOfEyes) {
+                Point eyeCenter = new Point(face.x + eye.x + eye.width / 2, face.y + eye.y + eye.height / 2);
+                int radius = (int) Math.round((eye.width + eye.height) * 0.25);
+                Imgproc.circle(frame, eyeCenter, radius, new Scalar(255, 0, 0), 4);
+            }
+        }
+
+        //-- Show what you got
+        HighGui.imshow("Capture - Face detection", frame );
+    }
+
+    public void run(String[] args) {
+        String filenameFaceCascade = args.length > 2 ? args[0] : "../../data/haarcascades/haarcascade_frontalface_alt.xml";
+        String filenameEyesCascade = args.length > 2 ? args[1] : "../../data/haarcascades/haarcascade_eye_tree_eyeglasses.xml";
+        int cameraDevice = args.length > 2 ? Integer.parseInt(args[2]) : 0;
+
+        CascadeClassifier faceCascade = new CascadeClassifier();
+        CascadeClassifier eyesCascade = new CascadeClassifier();
+
+        if (!faceCascade.load(filenameFaceCascade)) {
+            System.err.println("--(!)Error loading face cascade: " + filenameFaceCascade);
+            System.exit(0);
+        }
+        if (!eyesCascade.load(filenameEyesCascade)) {
+            System.err.println("--(!)Error loading eyes cascade: " + filenameEyesCascade);
+            System.exit(0);
+        }
+
+        VideoCapture capture = new VideoCapture(cameraDevice);
+        if (!capture.isOpened()) {
+            System.err.println("--(!)Error opening video capture");
+            System.exit(0);
+        }
+
+        Mat frame = new Mat();
+        while (capture.read(frame)) {
+            if (frame.empty()) {
+                System.err.println("--(!) No captured frame -- Break!");
+                break;
+            }
+
+            //-- 3. Apply the classifier to the frame
+            detectAndDisplay(frame, faceCascade, eyesCascade);
+
+            if (HighGui.waitKey(10) == 27) {
+                break;// escape
+            }
+        }
+
+        System.exit(0);
+    }
+}
+
+public class ObjectDetectionDemo {
+    public static void main(String[] args) {
+        // Load the native OpenCV library
+        System.loadLibrary(Core.NATIVE_LIBRARY_NAME);
+
+        new ObjectDetection().run(args);
+    }
+}

samples/java/tutorial_code/photo/hdr_imaging/HDRImagingDemo.java

+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Paths;
+import java.util.ArrayList;
+import java.util.List;
+
+import org.opencv.core.Core;
+import org.opencv.core.CvType;
+import org.opencv.core.Mat;
+import org.opencv.imgcodecs.Imgcodecs;
+import org.opencv.photo.CalibrateDebevec;
+import org.opencv.photo.MergeDebevec;
+import org.opencv.photo.MergeMertens;
+import org.opencv.photo.Photo;
+import org.opencv.photo.TonemapDurand;
+
+class HDRImaging {
+    public void loadExposureSeq(String path, List<Mat> images, List<Float> times) {
+        path += "/";
+
+        List<String> lines;
+        try {
+            lines = Files.readAllLines(Paths.get(path + "list.txt"));
+
+            for (String line : lines) {
+                String[] splitStr = line.split("\\s+");
+                if (splitStr.length == 2) {
+                    String name = splitStr[0];
+                    Mat img = Imgcodecs.imread(path + name);
+                    images.add(img);
+                    float val = Float.parseFloat(splitStr[1]);
+                    times.add(1/ val);
+                }
+            }
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+    }
+
+    public void run(String[] args) {
+        String path = args.length > 0 ? args[0] : "";
+        if (path.isEmpty()) {
+            System.out.println("Path is empty. Use the directory that contains images and exposure times.");
+            System.exit(0);
+        }
+
+        //! [Load images and exposure times]
+        List<Mat> images = new ArrayList<>();
+        List<Float> times = new ArrayList<>();
+        loadExposureSeq(path, images, times);
+        //! [Load images and exposure times]
+
+        //! [Estimate camera response]
+        Mat response = new Mat();
+        CalibrateDebevec calibrate = Photo.createCalibrateDebevec();
+        Mat matTimes = new Mat(times.size(), 1, CvType.CV_32F);
+        float[] arrayTimes = new float[(int) (matTimes.total()*matTimes.channels())];
+        for (int i = 0; i < times.size(); i++) {
+            arrayTimes[i] = times.get(i);
+        }
+        matTimes.put(0, 0, arrayTimes);
+        calibrate.process(images, response, matTimes);
+        //! [Estimate camera response]
+
+        //! [Make HDR image]
+        Mat hdr = new Mat();
+        MergeDebevec mergeDebevec = Photo.createMergeDebevec();
+        mergeDebevec.process(images, hdr, matTimes);
+        //! [Make HDR image]
+
+        //! [Tonemap HDR image]
+        Mat ldr = new Mat();
+        TonemapDurand tonemap = Photo.createTonemapDurand();
+        tonemap.process(hdr, ldr);
+        //! [Tonemap HDR image]
+
+        //! [Perform exposure fusion]
+        Mat fusion = new Mat();
+        MergeMertens mergeMertens = Photo.createMergeMertens();
+        mergeMertens.process(images, fusion);
+        //! [Perform exposure fusion]
+
+        //! [Write results]
+        fusion = fusion.mul(fusion, 255);
+        ldr = ldr.mul(ldr, 255);
+        Imgcodecs.imwrite("fusion.png", fusion);
+        Imgcodecs.imwrite("ldr.png", ldr);
+        Imgcodecs.imwrite("hdr.hdr", hdr);
+        //! [Write results]
+
+        System.exit(0);
+    }
+}
+
+public class HDRImagingDemo {
+    public static void main(String[] args) {
+        // Load the native OpenCV library
+        System.loadLibrary(Core.NATIVE_LIBRARY_NAME);
+
+        new HDRImaging().run(args);
+    }
+}

samples/python/tutorial_code/objectDetection/cascade_classifier/objectDetection.py

+from __future__ import print_function
+import cv2 as cv
+import argparse
+
+def detectAndDisplay(frame):
+    frame_gray = cv.cvtColor(frame, cv.COLOR_BGR2GRAY)
+    frame_gray = cv.equalizeHist(frame_gray)
+
+    #-- Detect faces
+    faces = face_cascade.detectMultiScale(frame_gray)
+    for (x,y,w,h) in faces:
+        center = (x + w//2, y + h//2)
+        frame = cv.ellipse(frame, center, (w//2, h//2), 0, 0, 360, (255, 0, 255), 4)
+
+        faceROI = frame_gray[y:y+h,x:x+w]
+        #-- In each face, detect eyes
+        eyes = eyes_cascade.detectMultiScale(faceROI)
+        for (x2,y2,w2,h2) in eyes:
+            eye_center = (x + x2 + w2//2, y + y2 + h2//2)
+            radius = int(round((w2 + h2)*0.25))
+            frame = cv.circle(frame, eye_center, radius, (255, 0, 0 ), 4)
+
+    cv.imshow('Capture - Face detection', frame)
+
+parser = argparse.ArgumentParser(description='Code for Cascade Classifier tutorial.')
+parser.add_argument('--face_cascade', help='Path to face cascade.', default='../../data/haarcascades/haarcascade_frontalface_alt.xml')
+parser.add_argument('--eyes_cascade', help='Path to eyes cascade.', default='../../data/haarcascades/haarcascade_eye_tree_eyeglasses.xml')
+parser.add_argument('--camera', help='Camera devide number.', type=int, default=0)
+args = parser.parse_args()
+
+face_cascade_name = args.face_cascade
+eyes_cascade_name = args.eyes_cascade
+
+face_cascade = cv.CascadeClassifier()
+eyes_cascade = cv.CascadeClassifier()
+
+#-- 1. Load the cascades
+if not face_cascade.load(face_cascade_name):
+    print('--(!)Error loading face cascade')
+    exit(0)
+if not eyes_cascade.load(eyes_cascade_name):
+    print('--(!)Error loading eyes cascade')
+    exit(0)
+
+camera_device = args.camera
+#-- 2. Read the video stream
+cap = cv.VideoCapture(camera_device)
+if not cap.isOpened:
+    print('--(!)Error opening video capture')
+    exit(0)
+
+while True:
+    ret, frame = cap.read()
+    if frame is None:
+        print('--(!) No captured frame -- Break!')
+        break
+
+    detectAndDisplay(frame)
+
+    if cv.waitKey(10) == 27:
+        break

samples/python/tutorial_code/photo/hdr_imaging/hdr_imaging.py

+from __future__ import print_function
+from __future__ import division
+import cv2 as cv
+import numpy as np
+import argparse
+import os
+
+def loadExposureSeq(path):
+    images = []
+    times = []
+    with open(os.path.join(path, 'list.txt')) as f:
+        content = f.readlines()
+    for line in content:
+        tokens = line.split()
+        images.append(cv.imread(os.path.join(path, tokens[0])))
+        times.append(1 / float(tokens[1]))
+
+    return images, np.asarray(times, dtype=np.float32)
+
+parser = argparse.ArgumentParser(description='Code for High Dynamic Range Imaging tutorial.')
+parser.add_argument('--input', type=str, help='Path to the directory that contains images and exposure times.')
+args = parser.parse_args()
+
+if not args.input:
+    parser.print_help()
+    exit(0)
+
+## [Load images and exposure times]
+images, times = loadExposureSeq(args.input)
+## [Load images and exposure times]
+
+## [Estimate camera response]
+calibrate = cv.createCalibrateDebevec()
+response = calibrate.process(images, times)
+## [Estimate camera response]
+
+## [Make HDR image]
+merge_debevec = cv.createMergeDebevec()
+hdr = merge_debevec.process(images, times, response)
+## [Make HDR image]
+
+## [Tonemap HDR image]
+tonemap = cv.createTonemapDurand(2.2)
+ldr = tonemap.process(hdr)
+## [Tonemap HDR image]
+
+## [Perform exposure fusion]
+merge_mertens = cv.createMergeMertens()
+fusion = merge_mertens.process(images)
+## [Perform exposure fusion]
+
+## [Write results]
+cv.imwrite('fusion.png', fusion * 255)
+cv.imwrite('ldr.png', ldr * 255)
+cv.imwrite('hdr.hdr', hdr)
+## [Write results]