+
+bool
+valid_image_file (boost::filesystem::path f)
+{
+ string ext = f.extension().string();
+ transform (ext.begin(), ext.end(), ext.begin(), ::tolower);
+ return (ext == ".tif" || ext == ".tiff" || ext == ".jpg" || ext == ".jpeg" || ext == ".png" || ext == ".bmp" || ext == ".tga");
+}
+