Merge pull request #1224 from rolalaro/vpCircleHoughTransform

Small improvements in vpCircleHoughTransform

doc/tutorial/imgproc/tutorial-imgproc-cht.dox

@@ -144,7 +144,7 @@ You could have also used the following method to get only the `num_best` best
 detections:
 \code
 int num_best; // Set it to the number of circles you want to keep
-std::vector<vvpImageCircle> detections = detector.detect(I, num_best);
+std::vector<vpImageCircle> detections = detector.detect(I, num_best);
 \endcode
 
 Then, you can iterate on the vector of detections using a synthax similar to the following:

modules/core/include/visp3/core/vpImageCircle.h

@@ -47,6 +47,10 @@
 #include <visp3/core/vpImagePoint.h>
 #include <visp3/core/vpRect.h>
 
+#if defined(VISP_HAVE_OPENCV)
+#include <opencv2/core.hpp>
+#endif
+
 /**
    * \brief Class that defines a 2D circle in an image.
    */

modules/imgproc/include/visp3/imgproc/vpCircleHoughTransform.h

@@ -39,6 +39,7 @@
 
 // ViSP includes
 #include <visp3/core/vpConfig.h>
+#include <visp3/core/vpCannyEdgeDetection.h>
 #include <visp3/core/vpImage.h>
 #include <visp3/core/vpImageCircle.h>
 #include <visp3/core/vpImageDraw.h>
@@ -69,7 +70,7 @@ class VISP_EXPORT vpCircleHoughTransform
   /**
    * \brief Class that gather the algorithm parameters.
    */
-  class CHTransformParameters
+  class vpCircleHoughTransformParameters
   {
   private:
     // // Gaussian smoothing attributes
@@ -102,7 +103,7 @@ class VISP_EXPORT vpCircleHoughTransform
 
     friend class vpCircleHoughTransform;
   public:
-    CHTransformParameters()
+    vpCircleHoughTransformParameters()
       : m_gaussianKernelSize(5)
       , m_gaussianStdev(1.)
       , m_sobelKernelSize(3)
@@ -123,7 +124,7 @@ class VISP_EXPORT vpCircleHoughTransform
     }
 
     /**
-     * \brief Construct a new CHTransformParameters object.
+     * \brief Construct a new vpCircleHoughTransformParameters object.
      *
      * \param[in] gaussianKernelSize Size of the Gaussian filter kernel used to smooth the input image. Must be an odd number.
      * \param[in] gaussianStdev Standard deviation of the Gaussian filter.
@@ -142,7 +143,7 @@ class VISP_EXPORT vpCircleHoughTransform
      * \param[in] centerMinDistThresh  Two circle candidates whose centers are closer than this threshold are considered for merging.
      * \param[in] mergingRadiusDiffThresh Maximum radius difference between two circle candidates to consider merging them.
      */
-    CHTransformParameters(
+    vpCircleHoughTransformParameters(
         const int &gaussianKernelSize
       , const float &gaussianStdev
       , const int &sobelKernelSize
@@ -201,12 +202,12 @@ class VISP_EXPORT vpCircleHoughTransform
     // // Configuration from files
 #ifdef VISP_HAVE_NLOHMANN_JSON
   /**
-   * \brief Create a new CHTransformParameters from a JSON file.
+   * \brief Create a new vpCircleHoughTransformParameters from a JSON file.
    *
    * \param[in] jsonFile The path towards the JSON file.
-   * \return CHTransformParameters The corresponding CHTransformParameters object.
+   * \return vpCircleHoughTransformParameters The corresponding vpCircleHoughTransformParameters object.
    */
-    inline static CHTransformParameters createFromJSON(const std::string &jsonFile)
+    inline static vpCircleHoughTransformParameters createFromJSON(const std::string &jsonFile)
     {
       std::ifstream file(jsonFile);
       if (!file.good()) {
@@ -226,7 +227,7 @@ class VISP_EXPORT vpCircleHoughTransform
         msg << "Byte position of error: " << e.byte;
         throw vpException(vpException::ioError, msg.str());
       }
-      CHTransformParameters params = j; // Call from_json(const json& j, vpDetectorDNN& *this) to read json
+      vpCircleHoughTransformParameters params = j; // Call from_json(const json& j, vpDetectorDNN& *this) to read json
       file.close();
       return params;
     }
@@ -253,7 +254,7 @@ class VISP_EXPORT vpCircleHoughTransform
      * \param[in] j : The JSON object, resulting from the parsing of a JSON file.
      * \param[out] params : The circle Hough transform parameters that will be initialized from the JSON data.
      */
-    inline friend void from_json(const json &j, CHTransformParameters &params)
+    inline friend void from_json(const json &j, vpCircleHoughTransformParameters &params)
     {
       params.m_gaussianKernelSize = j.value("gaussianKernelSize", params.m_gaussianKernelSize);
       if ((params.m_gaussianKernelSize % 2) != 1) {
@@ -311,7 +312,7 @@ class VISP_EXPORT vpCircleHoughTransform
      * \param[out] j : A JSON parser object.
      * \param[in] params : The circle Hough transform parameters that will be serialized in the json object.
      */
-    inline friend void to_json(json &j, const CHTransformParameters &params)
+    inline friend void to_json(json &j, const vpCircleHoughTransformParameters &params)
     {
       std::pair<unsigned int, unsigned int> radiusLimits = { params.m_minRadius, params.m_maxRadius };
 
@@ -341,10 +342,10 @@ class VISP_EXPORT vpCircleHoughTransform
 
   /**
    * \brief Construct a new vpCircleHoughTransform object
-   * from a \b CHTransformParameters object.
+   * from a \b vpCircleHoughTransformParameters object.
    * \param[in] algoParams The parameters of the Circle Hough Transform.
    */
-  vpCircleHoughTransform(const CHTransformParameters &algoParams);
+  vpCircleHoughTransform(const vpCircleHoughTransformParameters &algoParams);
 
   /**
    * \brief Destroy the vp Circle Hough Transform object
@@ -452,7 +453,7 @@ class VISP_EXPORT vpCircleHoughTransform
    *
    * \param[in] algoParams The algorithm parameters.
    */
-  void init(const CHTransformParameters &algoParams);
+  void init(const vpCircleHoughTransformParameters &algoParams);
 
   /**
    * \brief Set the parameters of the Gaussian filter, that computes the
@@ -767,7 +768,7 @@ class VISP_EXPORT vpCircleHoughTransform
   void mergeCircleCandidates();
 
 
-  CHTransformParameters m_algoParams; /*!< Attributes containing all the algorithm parameters.*/
+  vpCircleHoughTransformParameters m_algoParams; /*!< Attributes containing all the algorithm parameters.*/
   // // Gaussian smoothing attributes
   vpArray2D<float> m_fg;
   vpArray2D<float> m_fgDg;
@@ -778,6 +779,7 @@ class VISP_EXPORT vpCircleHoughTransform
   vpImage<float> m_dIy; /*!< Gradient along the y-axis of the input image.*/
 
   // // Edge detection attributes
+  vpCannyEdgeDetection m_cannyVisp; /*!< Edge detector ViSP implementation, used if ViSP has not been compiled with OpenCV imgproc module*/
   vpImage<unsigned char> m_edgeMap; /*!< Edge map resulting from the edge detection algorithm.*/
 
   // // Center candidates computation attributes

modules/imgproc/src/vpCircleHoughTransform.cpp

@@ -43,14 +43,14 @@ vpCircleHoughTransform::vpCircleHoughTransform()
   initGaussianFilters();
 }
 
-vpCircleHoughTransform::vpCircleHoughTransform(const CHTransformParameters &algoParams)
+vpCircleHoughTransform::vpCircleHoughTransform(const vpCircleHoughTransformParameters &algoParams)
   : m_algoParams(algoParams)
 {
   initGaussianFilters();
 }
 
 void
-vpCircleHoughTransform::init(const CHTransformParameters &algoParams)
+vpCircleHoughTransform::init(const vpCircleHoughTransformParameters &algoParams)
 {
   m_algoParams = algoParams;
   initGaussianFilters();
@@ -105,6 +105,7 @@ vpCircleHoughTransform::initGaussianFilters()
   vpImageFilter::getGaussianKernel(m_fg.data, m_algoParams.m_gaussianKernelSize, m_algoParams.m_gaussianStdev, false);
   m_fgDg.resize(1, (m_algoParams.m_gaussianKernelSize + 1)/2);
   vpImageFilter::getGaussianDerivativeKernel(m_fgDg.data, m_algoParams.m_gaussianKernelSize, m_algoParams.m_gaussianStdev, false);
+  m_cannyVisp.setGaussianFilterParameters(m_algoParams.m_gaussianKernelSize, m_algoParams.m_gaussianStdev);
 }
 
 std::vector<vpImageCircle>
@@ -218,10 +219,20 @@ vpCircleHoughTransform::computeGradientsAfterGaussianSmoothing(const vpImage<uns
 void
 vpCircleHoughTransform::edgeDetection(const vpImage<unsigned char> &I)
 {
-  int cannyThresh = m_algoParams.m_cannyThresh;
+#if defined(HAVE_OPENCV_IMGPROC)
+  float cannyThresh = m_algoParams.m_cannyThresh;
+  double lowerThresh;
   // Apply the Canny edge operator to compute the edge map
   // The canny method performs Gaussian blur and gradient computation
+  if (m_algoParams.m_cannyThresh < 0.) {
+    cannyThresh = vpImageFilter::computeCannyThreshold(I, lowerThresh);
+  }
   vpImageFilter::canny(I, m_edgeMap, m_algoParams.m_gaussianKernelSize, cannyThresh, m_algoParams.m_sobelKernelSize);
+#else
+  m_cannyVisp.setCannyThresholds(-1, m_algoParams.m_cannyThresh);
+  m_cannyVisp.setGradients(m_dIx, m_dIy);
+  m_edgeMap = m_cannyVisp.detect(I);
+#endif
 
   for (int i = 0; i < m_algoParams.m_edgeMapFilteringNbIter; i++) {
     filterEdgeMap();

tutorial/imgproc/hough-transform/tutorial-circle-hough.cpp

@@ -198,7 +198,11 @@ int main(int argc, char **argv)
   const int def_gaussianKernelSize = 5;
   const double def_gaussianSigma = 1.;
   const int def_sobelKernelSize = 3;
+#ifdef HAVE_OPENCV_IMGPROC
   const double def_cannyThresh = 150.;
+#else
+  const double def_cannyThresh = 25.;
+#endif
   const int def_nbEdgeFilteringIter = 2;
   const std::pair<int, int> def_centerXlimits = std::pair<int, int>(0, 640);
   const std::pair<int, int> def_centerYlimits = std::pair<int, int>(0, 480);
@@ -423,13 +427,25 @@ int main(int argc, char **argv)
     TypeInputImage inputType = typeInputImageFromString(opt_input);
     switch (inputType) {
     case TypeInputImage::FULL_DISKS:
+#ifdef HAVE_OPENCV_IMGPROC
       opt_centerThresh = 100.;
+#else
+      opt_centerThresh = 75.;
+#endif
       break;
     case TypeInputImage::HALF_DISKS:
+#ifdef HAVE_OPENCV_IMGPROC
       opt_centerThresh = 50.;
+#else
+      opt_centerThresh = 25.;
+#endif
       break;
     case TypeInputImage::QUARTER_DISKS:
+#ifdef HAVE_OPENCV_IMGPROC
       opt_centerThresh = 25.;
+#else
+      opt_centerThresh = 15.;
+#endif
       break;
     default:
       throw(vpException(vpException::badValue, "Missing center threshold value to use with actual pictures as input. See the help for more information."));
@@ -441,7 +457,11 @@ int main(int argc, char **argv)
     TypeInputImage inputType = typeInputImageFromString(opt_input);
     switch (inputType) {
     case TypeInputImage::FULL_DISKS:
+#ifdef HAVE_OPENCV_IMGPROC
       opt_radiusThreshRatio = 5.;
+#else
+      opt_radiusThreshRatio = 1.;
+#endif
       break;
     case TypeInputImage::HALF_DISKS:
       opt_radiusThreshRatio = 2.;
@@ -455,7 +475,7 @@ int main(int argc, char **argv)
   }
 
   //! [Algo params]
-  vpCircleHoughTransform::CHTransformParameters
+  vpCircleHoughTransform::vpCircleHoughTransformParameters
     algoParams(opt_gaussianKernelSize
       , opt_gaussianSigma
       , opt_sobelKernelSize