Removed constness from the operator() member functions of the object_detector

since they logically modify the state of the object detector now that
we are exposing the state of the underlying image scanner.

dlib/image_processing/object_detector.h

@@ -52,7 +52,7 @@ namespace dlib
             >
         std::vector<rectangle> operator() (
             const image_type& img
-        ) const;
+        );
 
         template <
             typename image_type
@@ -60,7 +60,7 @@ namespace dlib
         void operator() (
             const image_type& img,
             std::vector<std::pair<double, rectangle> >& final_dets
-        ) const;
+        );
 
         template <typename T, typename U>
         friend void serialize (
@@ -104,7 +104,7 @@ namespace dlib
 
         overlap_tester_type boxes_overlap;
         matrix<double,0,1> w;
-        mutable image_scanner_type scanner;
+        image_scanner_type scanner;
     };
 
 // ----------------------------------------------------------------------------------------
@@ -228,7 +228,7 @@ namespace dlib
     std::vector<rectangle> object_detector<image_scanner_type,overlap_tester_type>::
     operator() (
         const image_type& img
-    ) const
+    ) 
     {
         std::vector<rectangle> final_dets;
         if (w.size() != 0)
@@ -264,7 +264,7 @@ namespace dlib
     operator() (
         const image_type& img,
         std::vector<std::pair<double, rectangle> >& final_dets
-    ) const
+    ) 
     {
         final_dets.clear();
         if (w.size() != 0)

dlib/image_processing/object_detector_abstract.h

@@ -111,7 +111,7 @@ namespace dlib
             >
         std::vector<rectangle> operator() (
             const image_type& img
-        ) const;
+        );
         /*!
             requires
                 - img == an object which can be accepted by image_scanner_type::load()
@@ -132,7 +132,7 @@ namespace dlib
         void operator() (
             const image_type& img,
             std::vector<std::pair<double, rectangle> >& dets 
-        ) const;
+        );
         /*!
             requires
                 - img == an object which can be accepted by image_scanner_type::load()

dlib/svm/cross_validate_object_detection_trainer.h

@@ -73,7 +73,7 @@ namespace dlib
         typename image_array_type
         >
     const matrix<double,1,2> test_object_detection_function (
-        const object_detector_type& detector,
+        object_detector_type& detector,
         const image_array_type& images,
         const std::vector<std::vector<rectangle> >& truth_rects,
         const double overlap_eps = 0.5

dlib/svm/cross_validate_object_detection_trainer_abstract.h

@@ -17,7 +17,7 @@ namespace dlib
         typename image_array_type
         >
     const matrix<double,1,2> test_object_detection_function (
-        const object_detector_type& detector,
+        object_detector_type& detector,
         const image_array_type& images,
         const std::vector<std::vector<rectangle> >& truth_rects,
         const double overlap_eps = 0.5