zephyrrr, the google china map(GoogleMapChina and GoogleLabelChina)'s Cordination System is Beijing54 but not WGS84. If you see GoogleHybridChina in china, such as "Ningbo, China", with some high zoom, you will find that the road in satellite and the road in map or label has some offset. In web, Google china make a dynamic offset in the map.
In the patch, i add offset support to PureImage, and the image wil be drawn with offset which is get from the special google china map url. 
Hope it can do some help.