# By max.maischein@econsult.de
#
# Simple recipe to create proper width= and height= attributes
# for <IMG> tags
	sub PNGsize( $ ) {
	  # Returns a 2 element array containing the width and height of the image
	  my $Buffer = shift;
	  my ($Width, $Height) = ( undef, undef );		# Assume failure

	  if ($Buffer =~ /IHDR(.{8})/) {
	    # Now save the numbers
	    my $Data = $1;
    
	    ($Width, $Height) = unpack( "NN", $Data );
	  } else { print "'$Filename' is no PNG image (or has weird format)\n"; };

	  return ($Width, $Height);
	};

	sub GIFsize( $ ) {
	  my $ID;
	  my $bytes = shift;
	  my ($Width, $Height) = (undef, undef);

	  if ($bytes =~ /^GIF8/) {
            ($ID, $Width, $Height) = unpack( "A6SS", $bytes );
	  } else {
	    print "imgsize:GIF:No GIF header found\n";
	  };

	  return ($Width,$Height);
	};

	sub JPGsize( $ ) {
	  my $buffer = shift;
	  my ($Width, $Height) = (undef, undef);
          my $SOF = pack("CC", 0xFF, 0xC0 );
          if ($buffer =~ /$SOF...(....)/ ) {
            $buffer = $1;
            ($Height,$Width) = unpack( "nn", $buffer );
          } else { print "imgsize:JPeG:No SOF header found\n"};  
	  return ($Width, $Height);
	};

	sub img {
	  my $Filename = shift;
          my $alt = shift || "";
	  my $attributes = shift || "";
          my $ID;

	  $alt =~ s/(.+)/ alt=\"$1\" /;

	  my $result;
	  my $absdir;

	  if (!defined( &dirname )) {
	    use File::Basename;
	  };
	  $absdir = dirname( $inputfile );
	  my( $absname ) = build_path( $absdir, $Filename );
	  #print $absname, "\n";

	  my ($Width, $Height) = (undef, undef);
	  my $SizeFunc = undef;					# assume failure

	  my $Buffer = "";

	  if ( open( IMGFILE, "<" . $absname )) {
	    binmode IMGFILE;
	    read( IMGFILE, $Buffer, 2048 ) or print "Error reading from '$absname' : $!\n";
	    close( IMGFILE ) or print "Error closing '$absname' : $!\n";
	  } else {
	    print "Error opening '$absname' : $!\n";
	    $Buffer = undef;
	  };

	  if (defined( $Buffer )) {
	    if ($Filename =~ /\.gif$/i) {
	      $SizeFunc = \&GIFsize;
            } elsif ($Filename =~ /\.jpe?g$/i) {
	      $SizeFunc = \&JPGsize;
            } elsif ($Filename =~ /\.png$/i) {
	      $SizeFunc = \&PNGsize;
            } else {
 	      print "\nUnknown file extension for image : $imagename (ignored)";
            };
	    if (defined( $SizeFunc )) {
	      ($Width, $Height) = &{$SizeFunc}( $Buffer );
	    };
	  };

	  $attributes .= ( $Width ? " width=\"$Width\"" : "" ) . ( $Height ? " height=\"$Height\"" : "" );

          $result = "<IMG src=\"$Filename\"" . $alt . $attributes . ">";
	  return( $result );
	};