Added the load_image() function which just looks at a file's extension and

then calls the appropriate image loading function.

dlib/image_io.h

@@ -6,6 +6,7 @@
 #include "image_loader/image_loader.h"
 #include "image_loader/png_loader.h"
 #include "image_loader/jpeg_loader.h"
+#include "image_loader/load_image.h"
 #include "image_saver/image_saver.h"
 #include "image_saver/save_png.h"
 

dlib/image_loader/load_image.h

+// Copyright (C) 2011  Davis E. King (davis@dlib.net), Nils Labugt
+// License: Boost Software License   See LICENSE.txt for the full license.
+#ifndef DLIB_LOAd_IMAGE_H__
+#define DLIB_LOAd_IMAGE_H__
+
+#include "load_image_abstract.h"
+#include "../string.h"
+#include "png_loader.h"
+#include "jpeg_loader.h"
+#include "image_loader.h"
+
+namespace dlib
+{
+    template <typename image_type>
+    void load_image (
+        image_type& image,
+        const std::string& file_name
+    )
+    {
+        const std::string extension = tolower(right_substr(file_name,"."));
+        if (extension == "bmp")
+            load_bmp(image, file_name);
+#ifdef DLIB_PNG_SUPPORT
+        else if (extension == "png")
+            load_png(image, file_name);
+#endif
+#ifdef DLIB_JPEG_SUPPORT
+        else if (extension == "jpeg" || extension == "jpg")
+            load_jpeg(image, file_name);
+#endif
+        else if (extension == "dng")
+            load_dng(image, file_name);
+        else
+        {
+            if (extension == "jpeg" || extension == "jpg")
+                throw image_load_error("DLIB_JPEG_SUPPORT not #defined: Unable to load image in file " + file_name);
+            else if (extension == "png")
+                throw image_load_error("DLIB_PNG_SUPPORT not #defined: Unable to load image in file " + file_name);
+            else
+                throw image_load_error("Unknown file extension: Unable to load image in file " + file_name);
+        }
+    }
+
+}
+
+#endif // DLIB_LOAd_IMAGE_H__ 
+

dlib/image_loader/load_image_abstract.h

+// Copyright (C) 2011  Davis E. King (davis@dlib.net), Nils Labugt
+// License: Boost Software License   See LICENSE.txt for the full license.
+#undef DLIB_LOAd_IMAGE_ABSTRACT_
+#ifdef DLIB_LOAd_IMAGE_ABSTRACT_
+
+#include "load_image_abstract.h"
+#include "../string.h"
+
+namespace dlib
+{
+    template <typename image_type>
+    void load_image (
+        image_type& image,
+        const std::string& file_name
+    );
+    /*!
+        requires
+            - image_type == is an implementation of array2d/array2d_kernel_abstract.h
+            - pixel_traits<typename image_type::type> is defined  
+        ensures
+            - let EXT == the extension of the file given by file_name converted
+              to lower case (i.e.  the part of the file after the '.')
+            - if (EXT == "png") then
+                - performs: load_png(image, file_name);
+            - else if (EXT == "jpg" || EXT == "jpeg") then
+                - performs: load_jpeg(image, file_name);
+            - else if (EXT == "bmp") then
+                - performs: load_bmp(image, file_name);
+            - else if (EXT == "dng") then
+                - performs: load_dng(image, file_name);
+            - else
+                - throws image_load_error
+        throws
+            - image_load_error
+                This exception is thrown if there is some error that prevents
+                us from loading the given image file.
+    !*/
+
+}
+
+#endif // DLIB_LOAd_IMAGE_ABSTRACT_ 
+
+