added automatic onversion to byte if the out pixel type is not supported by the requested file format refactored above conversion into separate functions
added automatic onversion to byte if the out pixel type is not supported by the requested file format
refactored above conversion into separate functions

xiwei-zhang/vigra,mmuellner/vigra,timoMa/vigra,DaveRichmond-/vigra,hmeine/vigra,kod3r/vigra,ThomasWalter/vigra,hmeine/vigra,cbecker/vigra,xiwei-zhang/vigra,cha007/vigra,cha007/vigra,martinsch/vigra,DaveRichmond-/vigra,dstoe/vigra,kod3r/vigra,timoMa/vigra,stuarteberg/vigra,stuarteberg/vigra,hmeine/vigra,dstoe/vigra,mmuellner/vigra,dstoe/vigra,stuarteberg/vigra,kod3r/vigra,dstoe/vigra,capturePointer/vigra,cbecker/vigra,mmuellner/vigra,mmuellner/vigra,mmuellner/vigra,cha007/vigra,cha007/vigra,timoMa/vigra,DaveRichmond-/vigra,capturePointer/vigra,dagophil/vigra,stuarteberg/vigra,xiwei-zhang/vigra,capturePointer/vigra,dstoe/vigra,funkey/vigra,dagophil/vigra,capturePointer/vigra,psteinb/vigra,capturePointer/vigra,funkey/vigra,dagophil/vigra,kod3r/vigra,cbecker/vigra,psteinb/vigra,xiwei-zhang/vigra,hmeine/vigra,ThomasWalter/vigra,DaveRichmond-/vigra,xiwei-zhang/vigra,cbecker/vigra,funkey/vigra,martinsch/vigra,ThomasWalter/vigra,psteinb/vigra,psteinb/vigra,timoMa/vigra,martinsch/vigra,mmuellner/vigra,cha007/vigra,ThomasWalter/vigra,funkey/vigra,ThomasWalter/vigra,psteinb/vigra,cbecker/vigra,funkey/vigra,timoMa/vigra,martinsch/vigra,martinsch/vigra,DaveRichmond-/vigra,funkey/vigra,dagophil/vigra,kod3r/vigra,hmeine/vigra,ThomasWalter/vigra,dagophil/vigra,cha007/vigra,DaveRichmond-/vigra,cbecker/vigra,DaveRichmond-/vigra,stuarteberg/vigra,psteinb/vigra,mmuellner/vigra,capturePointer/vigra,dstoe/vigra,xiwei-zhang/vigra,dagophil/vigra,hmeine/vigra,kod3r/vigra,dagophil/vigra,martinsch/vigra,timoMa/vigra,xiwei-zhang/vigra,ThomasWalter/vigra,timoMa/vigra,stuarteberg/vigra,funkey/vigra,cha007/vigra,capturePointer/vigra,kod3r/vigra,psteinb/vigra,dstoe/vigra,stuarteberg/vigra,hmeine/vigra