performance improvement to usImage::CopyToImage  - only do stretch computation on pixels inside the hi/lo range. this is a big win when subframes are being used since in that case almost all the pixels are black and need not be stretched.  (hot spot found with cpu profiling) 
performance improvement to usImage::CopyToImage
 - only do stretch computation on pixels inside the hi/lo range. this is a big win when subframes are being used since in that case almost all the pixels are black and need not be stretched.
 (hot spot found with cpu profiling) 

hholi/phd2,hholi/phd2,eklenske/phd2,OpenPHDGuiding/phd2,OpenPHDGuiding/phd2,EverettQuebral/phd2,olegkutkov/phd2guiding_crao,hholi/phd2,eklenske/phd2,simonct/phd2,eklenske/phd2,olegkutkov/phd2guiding_crao,hholi/phd2,EverettQuebral/phd2,OpenPHDGuiding/phd2,lynxdeterra/open-phd-guiding,eklenske/phd2,lynxdeterra/open-phd-guiding,lynxdeterra/open-phd-guiding,eklenske/phd2,lynxdeterra/open-phd-guiding,olegkutkov/phd2guiding_crao,simonct/phd2,lynxdeterra/open-phd-guiding,hholi/phd2,simonct/phd2,olegkutkov/phd2guiding_crao,eklenske/phd2,olegkutkov/phd2guiding_crao,lynxdeterra/open-phd-guiding,EverettQuebral/phd2,hholi/phd2,EverettQuebral/phd2,OpenPHDGuiding/phd2,EverettQuebral/phd2,simonct/phd2,olegkutkov/phd2guiding_crao,EverettQuebral/phd2,simonct/phd2,simonct/phd2,OpenPHDGuiding/phd2,OpenPHDGuiding/phd2