Add sample code to compare the results across the different auto Gamm…

…a methods.

tutorial/imgproc/brightness/CMakeLists.txt

@@ -6,7 +6,9 @@ find_package(VISP REQUIRED visp_core visp_io visp_gui visp_imgproc)
 
 # set the list of source files
 set(tutorial_cpp
-  tutorial-brightness-adjustment.cpp)
+  tutorial-brightness-adjustment.cpp
+  tutorial-compare-auto-gamma.cpp
+)
 
 list(APPEND tutorial_data "${CMAKE_CURRENT_SOURCE_DIR}/Sample_low_brightness.png")
 

tutorial/imgproc/brightness/tutorial-brightness-adjustment.cpp

@@ -18,12 +18,12 @@
 #include <memory>
 #endif
 
-namespace
-{
 #ifdef ENABLE_VISP_NAMESPACE
 using namespace VISP_NAMESPACE_NAME;
 #endif
 
+namespace
+{
 void display(vpImage<vpRGBa> &I_display, vpImage<vpRGBa> &I_color_res, const vpImage<vpRGBa> &I_color_adjust,
   vpImage<unsigned char> &I_gray_res, vpImage<unsigned char> &I_gray_adjust, vpImage<vpRGBa> &I_gray_display,
   const std::string &title, const std::string &filename_color, const std::string &filename_gray,
@@ -57,9 +57,6 @@ int main(int argc, const char **argv)
   (defined(VISP_HAVE_PNG) || defined(VISP_HAVE_OPENCV) || defined(VISP_HAVE_STBIMAGE) || defined(VISP_HAVE_SIMDLIB)) && \
   ((__cplusplus >= 201103L) || (defined(_MSVC_LANG) && (_MSVC_LANG >= 201103L)))
   //! [Macro defined]
-#ifdef ENABLE_VISP_NAMESPACE
-  using namespace VISP_NAMESPACE_NAME;
-#endif
 
   std::string input_filename = "Sample_low_brightness.png";
   double alpha = 10.0, beta = 50.0;
@@ -122,16 +119,13 @@ int main(int argc, const char **argv)
     else if (std::string(argv[i]) == "--help" || std::string(argv[i]) == "-h") {
       std::cout << "Usage: " << argv[0]
         << " [--input <input image>]"
-        " [--alpha <alpha for VISP_NAMESPACE_NAME::adjust()>] [--beta <beta for "
-        "VISP_NAMESPACE_NAME::adjust()>]"
-        " [--gamma <gamma for VISP_NAMESPACE_NAME::gammaCorrection()>]"
+        " [--alpha <alpha for adjust()>] [--beta <beta for adjust()>]"
+        " [--gamma <gamma for gammaCorrection()>]"
         " [--gamma-color-handling " << VISP_NAMESPACE_NAME::vpGammaColorHandlingList() << "]"
         " [--gamma-method " << VISP_NAMESPACE_NAME::vpGammaMethodList() << "]"
-        " [--scale <scale for VISP_NAMESPACE_NAME::retinex()> [--scaleDiv for "
-        "VISP_NAMESPACE_NAME::retinex()]"
-        " [--level <level for VISP_NAMESPACE_NAME::retinex()> [--kernelSize "
-        "<kernelSize for VISP_NAMESPACE_NAME::retinex()>]"
-        " [--dynamic <dynamic for VISP_NAMESPACE_NAME::retinex()>] "
+        " [--scale <scale for retinex()> [--scaleDiv for retinex()]"
+        " [--level <level for retinex()> [--kernelSize <kernelSize for retinex()>]"
+        " [--dynamic <dynamic for retinex()>] "
         " [--scale-display <display downscaling factor>] "
         " [--help]"
         << std::endl;

tutorial/imgproc/brightness/tutorial-compare-auto-gamma.cpp

@@ -0,0 +1,259 @@
+//! \example tutorial-compare-auto-gamma
+
+#include <iostream>
+#include <visp3/core/vpConfig.h>
+#include <visp3/core/vpImage.h>
+#include <visp3/core/vpIoTools.h>
+#include <visp3/core/vpImageTools.h>
+#include <visp3/core/vpCannyEdgeDetection.h>
+#include <visp3/core/vpImageFilter.h>
+#include <visp3/core/vpFont.h>
+#include <visp3/io/vpImageIo.h>
+#include <visp3/io/vpVideoReader.h>
+
+// VISP_HAVE_SIMDLIB is required for INTERPOLATION_AREA
+#if defined(VISP_HAVE_MODULE_IMGPROC) && defined(VISP_HAVE_SIMDLIB) && \
+  ((__cplusplus >= 201103L) || (defined(_MSVC_LANG) && (_MSVC_LANG >= 201103L)))
+#include <visp3/imgproc/vpImgproc.h>
+#include <memory>
+
+#ifdef ENABLE_VISP_NAMESPACE
+using namespace VISP_NAMESPACE_NAME;
+#endif
+
+namespace
+{
+template <class T>
+void computeMeanMaxStdev(const vpImage<T> &I, float &mean, float &max, float &stdev)
+{
+  max = std::numeric_limits<float>::epsilon();
+  mean = 0.;
+  stdev = 0.;
+  unsigned int nbRows = I.getRows();
+  unsigned int nbCols = I.getCols();
+  float scale = 1.f / (static_cast<float>(nbRows) * static_cast<float>(nbCols));
+  for (unsigned int r = 0; r < nbRows; r++) {
+    for (unsigned int c = 0; c < nbCols; c++) {
+      mean += I[r][c];
+      max = std::max<float>(max, static_cast<float>(I[r][c]));
+    }
+  }
+  mean *= scale;
+  for (unsigned int r = 0; r < nbRows; r++) {
+    for (unsigned int c = 0; c < nbCols; c++) {
+      stdev += (I[r][c] - mean) * (I[r][c] - mean);
+    }
+  }
+  stdev *= scale;
+  stdev = std::sqrt(stdev);
+}
+
+void computeCanny(const vpImage<unsigned char> &I, vpCannyEdgeDetection &cannyDetector, int gaussianKernelSize,
+  float gaussianStdev, int apertureSize, vpImageFilter::vpCannyFilteringAndGradientType filteringType,
+  vpImage<unsigned char> &dIxy_uchar, vpImage<unsigned char> &I_canny_visp)
+{
+  vpImage<float> dIx, dIy, dIxy(I.getHeight(), I.getWidth());
+  vpImageFilter::computePartialDerivatives(I, dIx, dIy, true, true, true, gaussianKernelSize, gaussianStdev,
+      apertureSize, filteringType);
+
+  for (unsigned int i = 0; i < dIx.getHeight(); i++) {
+    for (unsigned int j = 0; j < dIx.getWidth(); j++) {
+      dIxy[i][j] = std::sqrt(dIx[i][j]*dIx[i][j] + dIy[i][j]*dIy[i][j]);
+    }
+  }
+
+  float mean, max, stdev;
+  computeMeanMaxStdev(dIxy, mean, max, stdev);
+  vpImageConvert::convert(dIx, dIxy_uchar);
+
+  // Set the gradients of the vpCannyEdgeDetection
+  cannyDetector.setGradients(dIx, dIy);
+
+  I_canny_visp = cannyDetector.detect(I);
+}
+} // namespace
+
+int main(int argc, const char **argv)
+{
+  std::string input = "Sample_low_brightness.png";
+  std::string output = "Results";
+  int gaussianKernelSize = 3;
+  float gaussianStdev = 1.;
+  int apertureSize = 3;
+  bool half = false;
+  vpImageFilter::vpCannyFilteringAndGradientType filteringType = vpImageFilter::CANNY_GBLUR_SOBEL_FILTERING;
+  VISP_NAMESPACE_NAME::vpGammaColorHandling gamma_colorspace = VISP_NAMESPACE_NAME::GAMMA_HSV;
+
+  for (int i = 1; i < argc; i++) {
+    if (std::string(argv[i]) == "--input" && i + 1 < argc) {
+      ++i;
+      input = std::string(argv[i]);
+    }
+    else if (std::string(argv[i]) == "--half") {
+      half = true;
+    }
+    else if (std::string(argv[i]) == "--gaussian-kernel-size" && i + 1 < argc) {
+      ++i;
+      gaussianKernelSize = std::atoi(argv[i]);
+    }
+    else if (std::string(argv[i]) == "--gaussian-std" && i + 1 < argc) {
+      ++i;
+      gaussianStdev = std::atof(argv[i]);
+    }
+    else if (std::string(argv[i]) == "--aperture-size" && i + 1 < argc) {
+      ++i;
+      apertureSize = std::atoi(argv[i]);
+    }
+    else if (std::string(argv[i]) == "--canny-filtering-type" && i + 1 < argc) {
+      ++i;
+      int type = std::atoi(argv[i]);
+      if (type == 1) {
+        filteringType = vpImageFilter::CANNY_GBLUR_SCHARR_FILTERING;
+      }
+    }
+    else if (std::string(argv[i]) == "--gamma-rgb") {
+      gamma_colorspace = VISP_NAMESPACE_NAME::GAMMA_RGB;
+    }
+    else if (std::string(argv[i]) == "--output" && i + 1 < argc) {
+      ++i;
+      output = std::string(argv[i]);
+    }
+    else {
+      std::cout << "Usage: " << argv[0]
+        << " [--input <input path or image sequence pattern>]"
+        " [--half (use half image resolution)]"
+        " [--gaussian-kernel-size <e.g. 3, 5, 7>]"
+        " [--gaussian-std <e.g. 1>]"
+        " [--aperture-size <e.g. 3>]"
+        " [--canny-filtering-type <0=CANNY_GBLUR_SOBEL_FILTERING, 1=CANNY_GBLUR_SCHARR_FILTERING>]"
+        " [--gamma-rgb (RGB colorspace, else HSV]"
+        " [--output <folder path> (to save results)]"
+        << std::endl;
+      return EXIT_SUCCESS;
+    }
+  }
+
+  std::cout << "Input: " << input << std::endl;
+  std::cout << "Process on half image resolution? " << half << std::endl;
+  std::cout << "Gaussian kernel size: " << gaussianKernelSize << std::endl;
+  std::cout << "Gaussian standard deviation: " << gaussianStdev << std::endl;
+  std::cout << "Aperture size: " << apertureSize << std::endl;
+  std::cout << "Canny filtering type: " << filteringType << std::endl;
+  std::cout << "RGB colorspace? " << (gamma_colorspace == VISP_NAMESPACE_NAME::GAMMA_RGB) << std::endl;
+  std::cout << "Output result folder: " << output << std::endl;
+
+  // Canny parameters
+  float lowerThresh = -1.;
+  float upperThresh = -1.;
+  float lowerThreshRatio = 0.6f;
+  float upperThreshRatio = 0.8f;
+  vpCannyEdgeDetection cannyDetector(gaussianKernelSize, gaussianStdev, apertureSize,
+                                    lowerThresh, upperThresh, lowerThreshRatio, upperThreshRatio,
+                                    filteringType);
+
+  bool single_image = vpIoTools::checkFilename(input);
+  vpVideoReader reader;
+  vpImage<vpRGBa> I_color_ori, I_color;
+  if (single_image) {
+    vpImageIo::read(I_color_ori, input);
+  }
+  else {
+    reader.setFileName(input);
+    reader.open(I_color_ori);
+  }
+  if (half) {
+    vpImageTools::resize(I_color_ori, I_color, I_color_ori.getWidth()/2, I_color_ori.getHeight()/2,
+      vpImageTools::INTERPOLATION_AREA);
+  }
+  else {
+    I_color = I_color_ori;
+  }
+
+  vpIoTools::makeDirectory(output);
+
+  vpImage<vpRGBa> I_color_gamma_correction, I_res_stack;
+  vpImage<unsigned char> I_gray_gamma_correction, dIxy_uchar, I_canny_visp;
+  vpImage<vpRGBa> dIxy_uchar_color, I_canny_visp_color;
+  vpFont font(32);
+  bool read_single_image = false;
+  while (!read_single_image && (single_image || !reader.end())) {
+    if (!single_image) {
+      reader.acquire(I_color_ori);
+    }
+    if (half) {
+      vpImageTools::resize(I_color_ori, I_color, I_color_ori.getWidth()/2, I_color_ori.getHeight()/2,
+        vpImageTools::INTERPOLATION_AREA);
+    }
+    else {
+      I_color = I_color_ori;
+    }
+
+    const int nb_methods = VISP_NAMESPACE_NAME::GAMMA_METHOD_COUNT - 1; // all except GAMMA_MANUAL
+    I_res_stack.init(nb_methods*I_color.getHeight(), 4*I_color.getWidth());
+    dIxy_uchar.init(I_color.getHeight(), I_color.getWidth());
+    I_canny_visp.init(I_color.getHeight(), I_color.getWidth());
+
+    // Output results
+    int offset_text_start_y = 25;
+    int text_h = 40;
+    int offset_idx = 0;
+    double start_time = 0, end_time = 0;
+    char buffer[FILENAME_MAX];
+
+    for (int gamma_idx = 1; gamma_idx < VISP_NAMESPACE_NAME::GAMMA_METHOD_COUNT; ++gamma_idx, offset_idx++) {
+      VISP_NAMESPACE_NAME::vpGammaMethod gamma_method = static_cast<VISP_NAMESPACE_NAME::vpGammaMethod>(gamma_idx);
+      if (gamma_method == VISP_NAMESPACE_NAME::GAMMA_MANUAL) {
+        continue;
+      }
+
+      const double gamma = -1;
+      start_time = vpTime::measureTimeMs();
+      VISP_NAMESPACE_NAME::gammaCorrection(I_color, I_color_gamma_correction, static_cast<float>(gamma),
+        gamma_colorspace, gamma_method);
+      end_time = vpTime::measureTimeMs();
+
+      vpImageConvert::convert(I_color_gamma_correction, I_gray_gamma_correction);
+      computeCanny(I_gray_gamma_correction, cannyDetector, gaussianKernelSize, gaussianStdev, apertureSize,
+        filteringType, dIxy_uchar, I_canny_visp);
+      vpImageConvert::convert(dIxy_uchar, dIxy_uchar_color);
+      vpImageConvert::convert(I_canny_visp, I_canny_visp_color);
+      I_res_stack.insert(I_color, vpImagePoint(offset_idx*I_color.getHeight(), 0));
+      I_res_stack.insert(I_color_gamma_correction, vpImagePoint(offset_idx*I_color.getHeight(), I_color.getWidth()));
+      I_res_stack.insert(I_canny_visp_color, vpImagePoint(offset_idx*I_color.getHeight(), 2*I_color.getWidth()));
+      I_res_stack.insert(dIxy_uchar_color, vpImagePoint(offset_idx*I_color.getHeight(), 3*I_color.getWidth()));
+      std::ostringstream oss;
+      oss <<  VISP_NAMESPACE_NAME::vpGammaMethodToString(gamma_method) << " (%.2f ms)";
+      snprintf(buffer, FILENAME_MAX, oss.str().c_str(), (end_time-start_time));
+      font.drawText(I_res_stack, buffer, vpImagePoint(offset_idx*I_color.getHeight() + offset_text_start_y,
+                                                      0.35*I_res_stack.getWidth()), vpColor::red);
+      snprintf(buffer, FILENAME_MAX, "Canny mean: (%.2f)", I_canny_visp.getMeanValue());
+      font.drawText(I_res_stack, buffer, vpImagePoint(offset_idx*I_color.getHeight() + offset_text_start_y+text_h,
+                                                      0.35*I_res_stack.getWidth()), vpColor::red);
+    }
+
+    if (!output.empty()) {
+      std::stringstream output_filename;
+      if (single_image) {
+        output_filename << vpIoTools::createFilePath(output, vpIoTools::getNameWE(input)) << ".png";
+      }
+      else {
+        output_filename << vpIoTools::createFilePath(output, vpIoTools::getNameWE(reader.getFrameName())) << ".png";
+      }
+      std::cout << "Write result to: " << output_filename.str() << std::endl;
+      vpImageIo::write(I_res_stack, output_filename.str());
+    }
+
+    if (single_image) {
+      read_single_image = true;
+    }
+  }
+
+  return EXIT_SUCCESS;
+}
+#else
+int main()
+{
+  std::cerr << "C++11 is required." << std::endl;
+  return EXIT_SUCCESS;
+}
+#endif