#@gimp High Pass: highpass_command, highpass_command_preview(0)
#@gimp : note = note("high pass filter")
#@gimp : sep = separator()
#@gimp : radius = float(5,0,100)
#@gimp : contrast = float(2,0,7)
#@gimp : invert = bool(0)
#@gimp : greyscale = bool(0)
#@gimp : sep = separator(), Preview type = choice("Full","Forward horizontal","Forward vertical","Backward horizontal","Backward vertical")
#***************************************************
# High Pass Filter with split preview
#***************************************************

highpass_command :
 --negative
 --if {$4==1} -to_gray -endif
 -gimp_gaussian_blur[1] $1,0,0,1,0,0,0
 -compose_interpolation
 -gimp_channel_processing 1,$2,0,0,0,0,100,256,0,0,0,2,0,0
 -if {$2>=4} 
 -gimp_channel_processing 1,{$2-3},0,0,0,0,100,256,0,0,0,2,0,0
 -endif
 -if {$3==1} -negative -endif 

highpass_command_preview :
  -gimp_split_preview "-highpass_command ${1--2}",$-1
#****END OF FILTER****