Automated GIMP Processing of Web Site Images

Listing 8. Show layers that have a name matching the given regular expression.

sub Layers_showByRE {
  my( $img, $layersre ) = @_;

  @layers = Gimp->image_get_layers( $img );
  foreach $l (@layers) {
    $n = Gimp->layer_get_name( $l );
    if( $n =~ m/$layersre/ )
      {
	Gimp->layer_set_visible( $l, 1 );
      }
  }
}
...
sub monkeyiq_gimp_layers_hideall {
  my($inputimagename,$outfilename,$layersre) = @_;

  $img = gimp_file_load( $inputimagename, 
                         $inputimagename );
  Layers_showByRE( $img, $layersre );

  gimp_xcf_save( 0, $img, 0, 
                 $outfilename, $outfilename );
  gimp_image_delete( $img );
}

Listing 9. Create a quick prelight image for mouse-over events.

...
sub monkeyiq_gimp_prelight {
  my($inputimagename,$outfilename, 
      $brightness, $contrast ) = @_;

  $img = gimp_file_load( $inputimagename, 
                         $inputimagename );

  print "prelight $inputimagename";
  print " to $outfilename\n";
  @layers = gimp_image_get_layers( $img );
  foreach $l (@layers)
    {
      gimp_brightness_contrast( $l, 
         $brightness, $contrast );
    }
  imageOutput( $img, $outfilename );
}
...
  "*",
  [
   [PF_STRING, "inputimage",  
     "Name of image to export", ""],
   [PF_STRING, "outputimage", 
     "Name of image to save to", ""],
   [PF_INT,    "brightness",  
     "-127 to 127", ""],
   [PF_INT,    "contrast",    
     "-127 to 127", ""],
  ],
...

Listing 10. Makefile to Convert xcf Files to Composited JPEG Images

tmp_img=/tmp/tmp_img.xcf
tmp2_img=/tmp/tmp_img.xcf
background_img=mybackground.png
simplelayered_extension=xcf
simplelayered_targets=\
  $(patsubst %.xcf,%.jpg,$(wildcard *.xcf))

all: $(simplelayered_targets)

$(simplelayered_targets): %.jpg: %.xcf 
	if_xcf=$<; \
	if=`basename $< .xcf`.png \
	of=$@; \
	of_thumbnail=`basename $@ .jpg`-thumb.jpg \
        gimp-monkeyiq-append-layer-from-image-file \
           -inputimage `pwd`/$$if_xcf \
           -outputimage $(tmp_img) \
           -layerimage `pwd`/$(background_img) \
	   -layername  "background-layer"; \
        gimp-monkeyiq-save-as-jpg \
           -inputimage  $(tmp_img)
           -outputimage $$of; \
        gimp-monkeyiq-scale \
           -inputimage  `pwd`/$$if_xcf \
           -outputimage $(tmp_img); \
	   -ratio 0.15; \
        gimp-monkeyiq-append-layer-from-image-file \
           -inputimage  $(tmp_img) \
           -outputimage $(tmp2_img) \
           -layerimage `pwd`/$(background_img) \
	   -layername  "background-layer"; \
        gimp-monkeyiq-layers-showall \
           -inputimage  $(tmp2_img) \
           -outputimage $(tmp_img); \
        gimp-monkeyiq-layers-hidebyre \
           -inputimage  $(tmp_img) \
           -outputimage $(tmp2_img) \
	   -layersre "background-layer"; \
        gimp-monkeyiq-move-visible-layers \
           -inputimage  $(tmp2_img) \
           -outputimage $(tmp_img) \
	   -xoffset 200 -yoffset 100; \
        gimp-monkeyiq-save-as-jpg \
           -inputimage $(tmp_img)
           -outputimage $$of;