add preset settings for the Image_describer to control the number of …

…detections. openMVG#269

src/nonFree/sift/SIFT_describer.hpp

@@ -84,6 +84,26 @@ class SIFT_Image_describer : public Image_describer
 
   ~SIFT_Image_describer() {}
 
+  bool Set_configuration_preset(EDESCRIBER_PRESET preset)
+  {
+    switch(preset)
+    {
+    case NORMAL_PRESET:
+      _params._peak_threshold = 0.04f;
+    break;
+    case HIGH_PRESET:
+      _params._peak_threshold = 0.01f;
+    break;
+    case ULTRA_PRESET:
+      _params._peak_threshold = 0.01f;
+      _params._first_octave = -1;
+    break;
+    default:
+      return false;
+    }
+    return true;
+  }
+
   /**
   @brief Detect regions on the image and compute their attributes (description)
   @param image Image.

src/openMVG/features/image_describer.hpp

@@ -17,13 +17,26 @@
 namespace openMVG {
 namespace features {
 
+enum EDESCRIBER_PRESET
+{
+  NORMAL_PRESET,
+  HIGH_PRESET,
+  ULTRA_PRESET
+};
 /// A pure virtual class for image description computation
 class Image_describer
 {
 public:
   Image_describer() {}
   virtual ~Image_describer() {}
 
+  /**
+  @brief Use a preset to control the number of detected regions
+  @param preset The preset configuration
+  @return True if configuration succeed.
+  */
+  virtual bool Set_configuration_preset(EDESCRIBER_PRESET preset) = 0;
+
   /**
   @brief Detect regions on the image and compute their attributes (description)
   @param image Image.

src/openMVG/features/image_describer_akaze.hpp

@@ -56,6 +56,26 @@ class AKAZE_Image_describer : public Image_describer
     bool bOrientation = true
   ):Image_describer(), _params(params), _bOrientation(bOrientation) {}
 
+
+  bool Set_configuration_preset(EDESCRIBER_PRESET preset)
+  {
+    switch(preset)
+    {
+    case NORMAL_PRESET:
+      _params._options.fThreshold = AKAZEConfig().fThreshold;
+    break;
+    case HIGH_PRESET:
+      _params._options.fThreshold = AKAZEConfig().fThreshold/10.;
+    break;
+    case ULTRA_PRESET:
+     _params._options.fThreshold = AKAZEConfig().fThreshold/100.;
+    break;
+    default:
+      return false;
+    }
+    return true;
+  }
+
   /**
   @brief Detect regions on the image and compute their attributes (description)
   @param image Image.