Package image implements evaluators of usage for images stored in an internal registry. They are supposed to be passed to resource quota controller and origin resource quota admission plugin. As opposed to kubernetes evaluators that can be used both with the controller and an admission plugin, these cannot. That's because they're counting a number of unique images which aren't namespaced. In order to do that they always need to enumerate all image streams in the project to see whether the newly tagged images are new to the project or not. The resource quota controller iterates over them implicitly while the admission plugin invokes the evaluator just once on a single object. Thus different usage implementations.
To instantiate a registry for use with the resource quota controller, use NewImageRegistry. To instantiate a registry for use with the origin resource quota admission plugin, use NewImageRegistryForAdmission.