png-cleanup.pl

   1 #!/usr/bin/perl
   2
   3 use strict;
   4 use warnings;
   5
   6 my $infile = shift ||
   7     die "no input file specified\n";
   8
   9 my $outfile = shift ||
  10     die "no outpu file specified\n";
  11
  12 # use the following to verify image attributes
  13 # identify -verbose <filename>
  14
  15 # set DPI to 146, so that we can display 1024 pixels (page width)
  16
  17 my $dpi = 146;
  18
  19 system("convert -units PixelsPerInch $infile -density $dpi $outfile");
  20
  21 # identify should return the same value
  22 # system("identify -units PixelsPerInch -format '%x x %y' $outfile");