Added get_feature_extractor() functions to the image scanners so the underlying

feature extractors can have their parameters queried.

dlib/image_processing/scan_image_boxes.h

@@ -74,6 +74,9 @@ namespace dlib
         const box_generator& get_box_generator (
         ) const { return detect_boxes; } 
 
+        const Feature_extractor_type& get_feature_extractor (
+        ) const { return feats; }
+
         inline void copy_configuration (
             const scan_image_boxes& item
         );

dlib/image_processing/scan_image_boxes_abstract.h

@@ -177,16 +177,23 @@ namespace dlib
                   false otherwise.
         !*/
 
+        const feature_extractor_type& get_feature_extractor (
+        ) const;
+        /*!
+            ensures
+                - returns a const reference to the feature_extractor_type object used 
+                  internally for local feature extraction.  
+        !*/
+
         void copy_configuration(
             const feature_extractor_type& fe
         );
         /*!
             ensures
-                - Let BASE_FE denote the feature_extractor_type object used internally for
-                  local feature extraction.  Then this function performs
-                  BASE_FE.copy_configuration(fe) (i.e. this function allows you to
-                  configure the parameters of the underlying feature extractor used by a
-                  scan_image_boxes object)
+                - This function performs the equivalent of
+                  get_feature_extractor().copy_configuration(fe) (i.e. this function allows
+                  you to configure the parameters of the underlying feature extractor used
+                  by a scan_image_boxes object)
         !*/
 
         void copy_configuration(

dlib/image_processing/scan_image_pyramid.h

@@ -51,6 +51,9 @@ namespace dlib
             const scan_image_pyramid& item
         );
 
+        const Feature_extractor_type& get_feature_extractor (
+        ) const { return feats_config; }
+
         void add_detection_template (
             const rectangle& object_box,
             const std::vector<rectangle>& stationary_feature_extraction_regions,

dlib/image_processing/scan_image_pyramid_abstract.h

@@ -150,16 +150,23 @@ namespace dlib
                   and false otherwise.
         !*/
 
+        const feature_extractor_type& get_feature_extractor (
+        ) const;
+        /*!
+            ensures
+                - returns a const reference to the feature_extractor_type object used 
+                  internally for local feature extraction.  
+        !*/
+
         void copy_configuration(
             const feature_extractor_type& fe
         );
         /*!
             ensures
-                - Let BASE_FE denote the feature_extractor_type object used
-                  internally for local feature extraction.  Then this function
-                  performs BASE_FE.copy_configuration(fe)
-                  (i.e. this function allows you to configure the parameters of the 
-                  underlying feature extractor used by a scan_image_pyramid object)
+                - This function performs the equivalent of
+                  get_feature_extractor().copy_configuration(fe) (i.e. this function allows
+                  you to configure the parameters of the underlying feature extractor used
+                  by a scan_image_pyramid object)
         !*/
 
         void copy_configuration (