SobelKernel       975 magick/morphology.c     case SobelKernel:       /* these are defined using other kernels */
SobelKernel      1367 magick/morphology.c     case SobelKernel:
SobelKernel      1146 magick/option.c     { "Sobel", SobelKernel, UndefinedOptionFlag, MagickFalse },