diff --git a/dlib/image_processing/object_detector.h b/dlib/image_processing/object_detector.h
index fdabeccf3..3bea05385 100644
--- a/dlib/image_processing/object_detector.h
+++ b/dlib/image_processing/object_detector.h
@@ -4,7 +4,6 @@
 #define DLIB_OBJECT_DeTECTOR_H__
 
 #include "object_detector_abstract.h"
-#include "../matrix.h"
 #include "../geometry.h"
 #include <vector>
 #include "box_overlap_testing.h"
@@ -21,6 +20,8 @@ namespace dlib
     class object_detector
     {
     public:
+        typedef typename image_scanner_type::feature_vector_type feature_vector_type;
+
         object_detector (
         );
 
@@ -31,11 +32,11 @@ namespace dlib
         object_detector (
             const image_scanner_type& scanner_, 
             const overlap_tester_type& overlap_tester_,
-            const matrix<double,0,1>& w_ 
+            const feature_vector_type& w_ 
         );
 
-        const matrix<double,0,1>& get_w (
-        ) const;
+        const feature_vector_type& get_w (
+        ) const { return w; }
 
         const overlap_tester_type& get_overlap_tester (
         ) const;
@@ -104,7 +105,7 @@ namespace dlib
         }
 
         overlap_tester_type boxes_overlap;
-        matrix<double,0,1> w;
+        feature_vector_type w;
         image_scanner_type scanner;
     };
 
@@ -178,7 +179,7 @@ namespace dlib
     object_detector (
         const image_scanner_type& scanner_, 
         const overlap_tester_type& overlap_tester,
-        const matrix<double,0,1>& w_ 
+        const feature_vector_type& w_ 
     ) :
         boxes_overlap(overlap_tester),
         w(w_)
@@ -288,19 +289,6 @@ namespace dlib
         }
     }
 
-// ----------------------------------------------------------------------------------------
-
-    template <
-        typename image_scanner_type,
-        typename overlap_tester_type
-        >
-    const matrix<double,0,1>& object_detector<image_scanner_type,overlap_tester_type>::
-    get_w (
-    ) const
-    {
-        return w;
-    }
-
 // ----------------------------------------------------------------------------------------
 
     template <
diff --git a/dlib/image_processing/object_detector_abstract.h b/dlib/image_processing/object_detector_abstract.h
index adabde2eb..3312b6b3e 100644
--- a/dlib/image_processing/object_detector_abstract.h
+++ b/dlib/image_processing/object_detector_abstract.h
@@ -3,7 +3,6 @@
 #undef DLIB_OBJECT_DeTECTOR_ABSTRACT_H__
 #ifdef DLIB_OBJECT_DeTECTOR_ABSTRACT_H__
 
-#include "../matrix.h"
 #include "../geometry.h"
 #include <vector>
 #include "box_overlap_testing_abstract.h"
@@ -37,6 +36,8 @@ namespace dlib
                 non-max suppression on the output of the scan_image_pyramid object.  
         !*/
     public:
+        typedef typename image_scanner_type::feature_vector_type feature_vector_type;
+
         object_detector (
         );
         /*!
@@ -59,7 +60,7 @@ namespace dlib
         object_detector (
             const image_scanner_type& scanner, 
             const overlap_tester_type& overlap_tester,
-            const matrix<double,0,1>& w 
+            const feature_vector_type& w 
         );
         /*!
             requires
@@ -81,7 +82,7 @@ namespace dlib
                   I.e. the copy is done using copy_configuration())
         !*/
 
-        const matrix<double,0,1>& get_w (
+        const feature_vector_type& get_w (
         ) const;
         /*!
             ensures