diff --git a/doc/tutorials/viz/histo3D/histo3D.markdown b/doc/tutorials/viz/histo3D/histo3D.markdown new file mode 100644 index 0000000000..fdf174cedd --- /dev/null +++ b/doc/tutorials/viz/histo3D/histo3D.markdown @@ -0,0 +1,51 @@ +Creating a 3D histogram {#tutorial_histo3D} +================ + +Goal +---- + +In this tutorial you will learn how to + +- Create your own callback keyboard function for viz window. +- Show your 3D histogram in a viz window. + +Code +---- + +You can download the code from [here ](https://github.com/opencv/opencv/tree/master/samples/cpp/tutorial_code/viz/histo3D.cpp). +@include samples/cpp/tutorial_code/viz/histo3D.cpp + +Explanation +----------- + +Here is the general structure of the program: + +- You can give full path to an image in command line + @snippet histo3D.cpp command_line_parser + + or without path, a synthetic image is generated with pixel values are a gaussian distribution @ref cv::RNG::fill center(60+/-10,40+/-5,50+/-20) in first quadrant, + (160+/-20,10+/-5,50+/-10) in second quadrant, (90+/-10,100+/-20,50+/-20) in third quadrant, (100+/-10,10+/-5,150+/-40) in last quadrant. + @snippet histo3D.cpp synthetic_image + Image tridimensional histogram is calculated using opencv @ref cv::calcHist and @ref cv::normalize between 0 and 100. + @snippet histo3D.cpp calchist_for_histo3d + channel are 2, 1 and 0 to synchronise color with Viz axis color in objetc cv::viz::WCoordinateSystem. + + A slidebar is inserted in image window. Init slidebar value is 90, it means that only histogram cell greater than 9/100000.0 (23 pixels for an 512X512 pixels) will be display. + @snippet histo3D.cpp slide_bar_for_thresh + We are ready to open a viz window with a callback function to capture keyboard event in viz window. Using @ref cv::viz::Viz3d::spinOnce enable keyboard event to be capture in @ref cv::imshow window too. + @snippet histo3D.cpp manage_viz_imshow_window + The function DrawHistogram3D processes histogram Mat to display it in a Viz window. Number of plan, row and column in [three dimensional Mat](@ref CVMat_Details ) can be found using this code : + @snippet histo3D.cpp get_cube_size + To get histogram value at a specific location we use @ref cv::Mat::at(int i0,int i1, int i2) method with three arguments k, i and j where k is plane number, i row number and j column number. + @snippet histo3D.cpp get_cube_values + +- Callback function + Principle are as mouse callback function. Key code pressed is in field code of class @ref cv::viz::KeyboardEvent. + @snippet histo3D.cpp viz_keyboard_callback + +Results +------- + +Here is the result of the program with no argument and threshold equal to 50. + +![](images/histo50.png) diff --git a/doc/tutorials/viz/histo3D/images/histo50.png b/doc/tutorials/viz/histo3D/images/histo50.png new file mode 100644 index 0000000000..b2b4416cee Binary files /dev/null and b/doc/tutorials/viz/histo3D/images/histo50.png differ diff --git a/doc/tutorials/viz/table_of_content_viz.markdown b/doc/tutorials/viz/table_of_content_viz.markdown index db20f1ee61..fae1396de4 100644 --- a/doc/tutorials/viz/table_of_content_viz.markdown +++ b/doc/tutorials/viz/table_of_content_viz.markdown @@ -32,3 +32,11 @@ OpenCV Viz {#tutorial_table_of_content_viz} *Author:* Ozan Tonkal You will learn how to create your own widgets. + +- @subpage tutorial_histo3D + + *Compatibility:* \> OpenCV 3.0.0 + + *Author:* Laurent Berger + + You will learn how to plot a 3D histogram. diff --git a/modules/core/include/opencv2/core/mat.hpp b/modules/core/include/opencv2/core/mat.hpp index 2e927c498c..e973593472 100644 --- a/modules/core/include/opencv2/core/mat.hpp +++ b/modules/core/include/opencv2/core/mat.hpp @@ -582,7 +582,7 @@ protected: An example demonstrating the serial out capabilities of cv::Mat */ - /** @brief n-dimensional dense array class + /** @brief n-dimensional dense array class \anchor CVMat_Details The class Mat represents an n-dimensional dense numerical single-channel or multi-channel array. It can be used to store real or complex-valued vectors and matrices, grayscale or color images, voxel diff --git a/samples/cpp/tutorial_code/viz/histo3D.cpp b/samples/cpp/tutorial_code/viz/histo3D.cpp new file mode 100644 index 0000000000..1b15737b9c --- /dev/null +++ b/samples/cpp/tutorial_code/viz/histo3D.cpp @@ -0,0 +1,184 @@ +#include +#include + +using namespace std; +using namespace cv; + +#ifdef HAVE_OPENCV_VIZ + +const String keys = +"{Aide h usage ? help | | print this message }" +"{@arg1 | | Full path to color imag (3 channels)}" +; + + +struct Histo3DData { + Mat histogram; + int seuil; + double threshold; + Ptr fen3D; + int nbWidget; + bool status; + double maxH; + int code; +}; + +void DrawHistogram3D(Histo3DData &); +void AddSlidebar(String sliderName, String windowName, int sliderMin, int sliderMax, int valeurDefaut, int *sliderVal, void(*f)(int, void *), void *r); +void UpdateThreshold(int , void * r); +void KeyboardViz3d(const viz::KeyboardEvent &w, void *t); + + +void DrawHistogram3D(Histo3DData &h) +{ + //! [get_cube_size] + int planSize = h.histogram.step1(0); + int cols = h.histogram.step1(1); + int rows = planSize / cols; + int plans = h.histogram.total() / planSize; + h.fen3D->removeAllWidgets(); + h.nbWidget=0; + if (h.nbWidget==0) + h.fen3D->showWidget("Axis", viz::WCoordinateSystem(10)); + //! [get_cube_size] + //! [get_cube_values] + for (int k = 0; k < plans; k++) + { + for (int i = 0; i < rows; i++) + { + for (int j = 0; j < cols; j++) + { + double x = h.histogram.at(k, i, j); + if (x >= h.threshold) + { + double r=std::max(x/h.maxH,0.1); + viz::WCube s(Point3d(k - r / 2, i - r / 2, j - r / 2), Point3d(k + r / 2, i + r / 2, j + r / 2), false, viz::Color(j / double(plans) * 255, i / double(rows) * 255, k / double(cols) * 255)); + h.fen3D->showWidget(format("I3d%d", h.nbWidget++), s); + } + } + } + } + //! [get_cube_values] + h.status = false; +} +//! [viz_keyboard_callback] +void KeyboardViz3d(const viz::KeyboardEvent &w, void *t) +{ + Histo3DData *x=(Histo3DData *)t; + if (w.action) + cout << "you pressed "<< w.symbol<< " in viz window "<fen3D->getWindowName()<<"\n"; + x->code= w.code; + switch (w.code) { + case '/': + x->status=true; + x->threshold *= 0.9; + break; + case '*': + x->status = true; + x->threshold *= 1.1; + break; + } + if (x->status) + { + cout << x->threshold << "\n"; + DrawHistogram3D(*x); + } +} +//! [viz_keyboard_callback] + + +void AddSlidebar(String sliderName, String windowName, int sliderMin, int sliderMax, int defaultSlider, int *sliderVal, void(*f)(int, void *), void *r) +{ + createTrackbar(sliderName, windowName, sliderVal, 1, f, r); + setTrackbarMin(sliderName, windowName, sliderMin); + setTrackbarMax(sliderName, windowName, sliderMax); + setTrackbarPos(sliderName, windowName, defaultSlider); +} + + +void UpdateThreshold(int , void * r) +{ + Histo3DData *h = (Histo3DData *)r; + h->status=true; + h->threshold = h->seuil/1000000.0; + cout<<"Widget : "<nbWidget<<","<< h->threshold<<"\n"; +} + +int main (int argc,char **argv) +{ + //! [command_line_parser] + CommandLineParser parser(argc, argv, keys); + + if (parser.has("help")) + { + parser.printMessage(); + return 0; + } + String nomFic = parser.get(0); + Mat img; + if (nomFic.length() != 0) + { + img = imread(nomFic, IMREAD_COLOR); + if (img.empty()) + { + cout << "Image does not exist!"; + return 0; + } + } + //! [command_line_parser] + //! [synthetic_image] + else + { + img = Mat(512,512,CV_8UC3); + parser.printMessage(); + RNG r; + r.fill(img(Rect(0, 0, 256, 256)), RNG::NORMAL, Vec3b(60, 40, 50), Vec3b(10, 5, 20)); + r.fill(img(Rect(256, 0, 256, 256)), RNG::NORMAL, Vec3b(160, 10, 50), Vec3b(20, 5, 10)); + r.fill(img(Rect(0, 256, 256, 256)), RNG::NORMAL, Vec3b(90, 100, 50), Vec3b(10, 20, 20)); + r.fill(img(Rect(256, 256, 256, 256)), RNG::NORMAL, Vec3b(100, 10, 150), Vec3b(10, 5, 40)); + } + //! [synthetic_image] + //! [calchist_for_histo3d] + Histo3DData h; + h.status=true; + h.seuil=90; + h.threshold= h.seuil/1000000.0; + float hRange[] = { 0, 256 }; + const float* etendu[] = { hRange, hRange,hRange }; + int hBins = 32; + int histSize[] = { hBins, hBins , hBins }; + int channel[] = { 2, 1,0 }; + calcHist(&img, 1, channel, Mat(), h.histogram, 3, histSize, etendu, true, false); + normalize(h.histogram, h.histogram, 100.0/(img.total()), 0, NORM_MINMAX, -1, Mat()); + minMaxIdx(h.histogram,NULL,&h.maxH,NULL,NULL); + //! [calchist_for_histo3d] + //! [slide_bar_for_thresh] + namedWindow("Image"); + imshow("Image",img); + AddSlidebar("threshold","Image",0,100,h.seuil,&h.seuil, UpdateThreshold,&h); + waitKey(30); + //! [slide_bar_for_thresh] + //! [manage_viz_imshow_window] + h.fen3D = new viz::Viz3d("3D Histogram"); + h.nbWidget=0; + h.fen3D->registerKeyboardCallback(KeyboardViz3d,&h); + DrawHistogram3D(h); + while (h.code!=27) + { + h.fen3D->spinOnce(1); + if (h.status) + DrawHistogram3D(h); + if (h.code!=27) + h.code= waitKey(30); + } + //! [manage_viz_imshow_window] + return 0; +} +#else + +int main(int argc, char **argv) +{ +cout << " you need VIZ module\n"; +return 0; +} +#endif