BUG: JPEG IO: only allow 8 bits
BUG: JPEG IO: only allow 8 bits

Important specially for external library. Not supported.

Kitware/ITK,InsightSoftwareConsortium/ITK,hjmjohnson/ITK,InsightSoftwareConsortium/ITK,InsightSoftwareConsortium/ITK,Kitware/ITK,hjmjohnson/ITK,InsightSoftwareConsortium/ITK,InsightSoftwareConsortium/ITK,richardbeare/ITK,InsightSoftwareConsortium/ITK,thewtex/ITK,hjmjohnson/ITK,BRAINSia/ITK,BRAINSia/ITK,InsightSoftwareConsortium/ITK,BRAINSia/ITK,Kitware/ITK,thewtex/ITK,thewtex/ITK,BRAINSia/ITK,Kitware/ITK,hjmjohnson/ITK,richardbeare/ITK,richardbeare/ITK,Kitware/ITK,BRAINSia/ITK,BRAINSia/ITK,thewtex/ITK,richardbeare/ITK,thewtex/ITK,Kitware/ITK,richardbeare/ITK,hjmjohnson/ITK,thewtex/ITK,thewtex/ITK,Kitware/ITK,hjmjohnson/ITK,richardbeare/ITK,hjmjohnson/ITK,BRAINSia/ITK,richardbeare/ITK