by **marcel.hauf**: <pre>The comment for Rectangle.Sub() says: "// Add returns the rectangle r translated by -p." It should probably say: "// Sub returns the rectangle r translated by -p." <a href="http://code.google.com/p/go/source/browse/src/pkg/image/geom.go#115">http://code.google.com/p/go/source/browse/src/pkg/image/geom.go#115</a></pre>