Manual:$wgDjvuPostProcessor

DjVu: $wgDjvuPostProcessor
Path of the DjVu post-processor.
Introduced in version:1.8.0 (r16036)
Removed in version:Still in use
Allowed values:(string)
Default value:'pnmtojpeg' (1.10+)
'ppmtojpeg' (1.8-1.9)

Details

Path of the DjVu post-processor. May include command line options. The output generated by $wgDjvuRenderer is passed onto this program.

The default: 'ppmtojpeg' is used, since ddjvu generates ppm output, which needs to be converted to JPEG to be viewed in browsers.

If your post-processor outputs anything other than .jpg files, you need to set $wgDjvuOutputExtension as well.

Change thumbnails to PNG

$wgDjvuPostProcessor = "pnmtopng";
$wgDjvuOutputExtension = "png";

See also