Generic filters are a catch-all for filters which can't be placed elsewhere.
This category describes the following filters:
第 9.2 节 “Convolution Matrix”
第 9.3 节 “Distance Map”
第 9.4 节 “Normal Map”
第 9.5 节 “Dilate”
第 9.6 节 “Erode”
第 9.7 节 “GEGL Graph”
