Yinpeng Jin Elsa D. Angelini Peter D. Esser Andrew Laine De-noising SPECT/PET Images Using Cross-Scale Regularization. 32-40 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=2879&spage=32 2003 conf/miccai/2003-2 MICCAI (2) db/conf/miccai/miccai2003-2.html#JinAEL03