Use ImageMagick to convert PNG background to transparent alpha

bgr.pl

#!/usr/bin/perl

$img = shift @ARGV;
$corner = `convert $img -format '%[pixel:s.p{0,0}]' info:`;
chomp $corner;
print "corner color is $corner\n";
@r = split(/\./, $img);
$ext = pop @r;
$name = join('.', @r); $name = $name . "_new." . $ext;
print "Saving to $name\n";
system("convert $img -alpha set -channel RGBA -fuzz 1% -fill none -floodfill +0+0 $corner $name");