Fixed const correctness on the in-memory jpeg loading code.

dlib/image_loader/jpeg_loader.cpp

@@ -49,7 +49,7 @@ namespace dlib
 // ----------------------------------------------------------------------------------------
     
     jpeg_loader::
-    jpeg_loader( unsigned char* imgbuffer, size_t imgbuffersize ) : height_( 0 ), width_( 0 ), output_components_(0)
+    jpeg_loader( const unsigned char* imgbuffer, size_t imgbuffersize ) : height_( 0 ), width_( 0 ), output_components_(0)
     {
         read_image( NULL, imgbuffer, imgbuffersize );
     }
@@ -113,7 +113,7 @@ namespace dlib
 
 // ----------------------------------------------------------------------------------------
 
-    void jpeg_loader::read_image( FILE * file, unsigned char* imgbuffer, size_t imgbuffersize )
+    void jpeg_loader::read_image( FILE * file, const unsigned char* imgbuffer, size_t imgbuffersize )
     {
         
         jpeg_decompress_struct cinfo;

dlib/image_loader/jpeg_loader.h

@@ -21,7 +21,7 @@ namespace dlib
         jpeg_loader( const char* filename );
         jpeg_loader( const std::string& filename );
         jpeg_loader( const dlib::file& f );
-        jpeg_loader( unsigned char* imgbuffer, size_t buffersize );
+        jpeg_loader( const unsigned char* imgbuffer, size_t buffersize );
 
         bool is_gray() const;
         bool is_rgb() const;
@@ -78,7 +78,7 @@ namespace dlib
         }
         
         FILE * check_file(const char* filename );
-        void read_image( FILE *file, unsigned char* imgbuffer, size_t imgbuffersize );
+        void read_image( FILE *file, const unsigned char* imgbuffer, size_t imgbuffersize );
         unsigned long height_; 
         unsigned long width_;
         unsigned long output_components_;
@@ -97,18 +97,31 @@ namespace dlib
     {
         jpeg_loader(file_name).get_image(image);
     }
+
     template <
         typename image_type
         >
     void load_jpeg (
         image_type& image,
-        unsigned char* imgbuff,
+        const unsigned char* imgbuff,
         size_t imgbuffsize
     )
     {
         jpeg_loader(imgbuff, imgbuffsize).get_image(image);
     }
 
+    template <
+        typename image_type
+        >
+    void load_jpeg (
+        image_type& image,
+        const char* imgbuff,
+        size_t imgbuffsize
+    )
+    {
+        jpeg_loader(reinterpret_cast<const unsigned char*>(imgbuff), imgbuffsize).get_image(image);
+    }
+
 // ----------------------------------------------------------------------------------------
 
 }

dlib/image_loader/jpeg_loader_abstract.h

@@ -66,7 +66,7 @@ namespace dlib
         !*/
 
         jpeg_loader( 
-            unsigned char* imgbuffer,
+            const unsigned char* imgbuffer,
             size_t buffersize
         );
         /*!
@@ -143,7 +143,7 @@ namespace dlib
         >
     void load_jpeg (
         image_type& image,
-        unsigned char* imgbuff,
+        const unsigned char* imgbuff,
         size_t imgbuffsize
     );
     /*!
@@ -154,6 +154,22 @@ namespace dlib
             - performs: jpeg_loader(imgbuff, imgbuffsize).get_image(image);
     !*/
 
+    template <
+        typename image_type
+        >
+    void load_jpeg (
+        image_type& image,
+        const char* imgbuff,
+        size_t imgbuffsize
+    );
+    /*!
+        requires
+            - image_type == an image object that implements the interface defined in
+              dlib/image_processing/generic_image.h 
+        ensures
+            - performs: jpeg_loader((unsigned char*)imgbuff, imgbuffsize).get_image(image);
+    !*/
+
 // ----------------------------------------------------------------------------------------
 
 }