Fixing appearance of Not-A-Number values when gradient is 0
Fixing appearance of Not-A-Number values when gradient is 0

jhlegarreta/ITKCuberille,thewtex/ITKCuberille,jhlegarreta/ITKCuberille,InsightSoftwareConsortium/ITKCuberille,InsightSoftwareConsortium/ITKCuberille,jhlegarreta/ITKCuberille,thewtex/ITKCuberille,thewtex/ITKCuberille,InsightSoftwareConsortium/ITKCuberille