+class unsupported_image_format: public std::runtime_error
+{
+public:
+ unsupported_image_format(const std::string &w): std::runtime_error(w) { }
+ virtual ~unsupported_image_format() throw() { }
+};
+
+class bad_image_data: public std::runtime_error
+{
+public:
+ bad_image_data(const std::string &w): std::runtime_error(w) { }
+ virtual ~bad_image_data() throw() { }
+};
+
+