my $background=Image::Magick->new(magick=>"gif");
    $background->BlobToImage($binary_data);

    my $foreground=Image::Magick->new;
    $foreground->Read($watermark_file);
    $foreground->Transparent(color=>"white");

    $background->Composite(compose=>'Over', Image=>$foreground, x=> 1, y=> 1) 

    $background->Write("gif-");
    
    $binary_data = $background->ImageToBlob();
    
    print "content-type: image/gif\n\n";
    print $binary_data;