added range check in cannyEdgeImage()
added range check in cannyEdgeImage()

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