SobelKernel       966 magick/morphology.c     case SobelKernel:       /* these are defined using other kernels */
SobelKernel      1324 magick/morphology.c     case SobelKernel:
SobelKernel      1095 magick/option.c     { "Sobel", (ssize_t) SobelKernel, MagickFalse },