From Stephan Huber, "attached you'll find the missing readObject-implementations for the imageio-plugin as suggested by Remo Eichenberger."

src/osgPlugins/imageio/ReaderWriterImageIO.cpp

@@ -254,7 +254,7 @@ osg::Image* CreateOSGImageFromCGImage(CGImageRef image_ref)
 {
     /* This code is adapted from Apple's Documentation found here:
      * http://developer.apple.com/documentation/GraphicsImaging/Conceptual/OpenGL-MacProgGuide/index.html
-     * Listing 9-4††Using a Quartz image as a texture source.
+     * Listing 9-4Using a Quartz image as a texture source.
      * Unfortunately, this guide doesn't show what to do about
      * non-RGBA image formats so I'm making the rest up
      * (and it's probably all wrong).
@@ -1295,6 +1295,16 @@ public:
 #endif
     }
 
+    virtual ReadResult readObject(std::istream& fin,const osgDB::ReaderWriter::Options* options =NULL) const
+    {
+        return readImage(fin, options);
+    }
+
+    virtual ReadResult readObject(const std::string& file, const osgDB::ReaderWriter::Options* options =NULL) const
+    {
+        return readImage(file, options);
+    }
+
 };
 
 // now register with Registry to instantiate the above