Fixed the width_step() member functions. They weren't defined in quite the

way they should have been.

dlib/array2d/array2d_kernel_1.h

@@ -287,7 +287,7 @@ namespace dlib
         long width_step (
         ) const
         {
-            return nc_;
+            return nc_*sizeof(T);
         }
 
     private:

dlib/array2d/array2d_kernel_abstract.h

@@ -209,8 +209,9 @@ namespace dlib
         ) const;
         /*!
             ensures
-                - returns the pointer offset to step from one row to another.
-                  That is, &item[0][0] + item.width_step() == &item[1][0].
+                - returns the size of one row of the image, in bytes.  
+                  More precisely, return a number N such that:
+                  (char*)&item[0][0] + N == (char*)&item[1][0].
         !*/
 
     private:

dlib/opencv/cv_image_abstract.h

@@ -146,8 +146,9 @@ namespace dlib
         ) const;
         /*!
             ensures
-                - returns the pointer offset to step from one row to another.
-                  That is, &item[0][0] + item.width_step() == &item[1][0].
+                - returns the size of one row of the image, in bytes.  
+                  More precisely, return a number N such that:
+                  (char*)&item[0][0] + N == (char*)&item[1][0].
         !*/
     };
 

dlib/test/array2d.cpp

@@ -545,6 +545,8 @@ namespace
                     DLIB_TEST(img[r][c] == img2[r][c]);
                 }
             }
+
+            DLIB_TEST((char*)&img[0][0] + img.width_step() == (char*)&img[1][0]);
         }
     }