| Image-Pbm documentation | Contained in the Image-Pbm distribution. |
Image::Pbm - Load, create, manipulate and save pbm image files.
use Image::Pbm();
my $i = Image::Pbm->new(-width => 50, -height => 25 );
$i->line ( 2, 2, 22, 22 => 1 );
$i->rectangle( 4, 4, 40, 20 => 1 );
$i->ellipse ( 6, 6, 30, 15 => 1 );
$i->xybit ( 42, 22 => 1 );
print $i->as_string;
$i->save('test.pbm');
$i = Image::Pbm->new(-file,'test.pbm');
This module provides basic load, manipulate and save functionality for
the pbm file format. It inherits from Image::Xbm which provides additional
functionality.
See Image::Base and Image::Xbm for a description of all inherited methods.
Imagine, we have to create self-contained web pages (with embedded images). Most browsers understand the xbm image format, but generating xbm files requires a certain effort (or a full fledged graphics software package). On the other hand, generating pbm files is easy. Indeed, it's more likely that you use your favorite text editor instead of Image::Pbm for that task. Reading pbm files is slightly more difficult. That's where the Image::[PX]bm modules come into play:
use Image::Pbm();
Image::Pbm->new(-file,'test.pbm')
->new_from_image('Image::Xbm')
->save('test.xbm');
Once we have xbm files, we can serve these images onto the Internet. To embed these images into a web page, we can use the "data" URL scheme:
http://www.ietf.org/rfc/rfc2397.txt
which requires the standard %xx hex encoding of URLs:
use URI::Escape(); my $data = URI::Escape::uri_escape( $xbm ); print qq(<img src="data:image/x-xbitmap,$data">);
This works with Mozilla and Opera. For Internet Explorer, we can use the following workaround:
print <<"HTML";
<pre id="xbm" style="display: none;">$xbm</pre>
<script>
function xbm() { return document.getElementById('xbm').innerHTML; }
</script>
<img src="javascript:xbm()">
HTML
This works with Mozilla too.
Contact Mark Summerfield because the inheritance hierarchy
Image::Pbm <: Image::Xbm <: Image::Base
is suboptimal and should look like
Image::Xbm <:
Image::Bitmap <: Image::Base
Image::Pbm <:
Steffen Goeldner <sgoeldner@cpan.org>
Copyright (c) 2004 Steffen Goeldner. All rights reserved.
This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.
perl, Image::Base, Image::Xbm, Image::PBMlib.
| Image-Pbm documentation | Contained in the Image-Pbm distribution. |
package Image::Pbm; our $VERSION = '0.03'; use strict; use warnings; use Image::Xbm(); our @ISA = 'Image::Xbm'; use Image::PBMlib(); sub load { my $self = shift ; my $file = shift || $self->get(-file ) or die 'No file specified'; open my $fh, $file or die "Failed to open `$file': $!"; my $h = Image::PBMlib::readppmheader( $fh ); die "Failed to parse header in `$file': $h->{error}" if $h->{error}; die "Wrong magic number: ($h->{type})" if $h->{type} != 1; $self->_set( -file => $file ); $self->_set( -width => $h->{width} ); $self->_set(-height => $h->{height} ); $self->_set( -bits => pack 'b*', join '', Image::PBMlib::readpixels_dec( $fh, $h->{type}, $h->{width} * $h->{height} ) ); } sub save { my $self = shift; my $file = shift || $self->get(-file ) or die 'No file specified'; # I hate getter/setter! They may be helpful in languages # which fail to hide the implementation of properties. my ( $setch, $unsetch ) = $self->get(-setch,-unsetch ); $self->set(-file => $file,-setch => ' 1',-unsetch => ' 0'); open my $fh, ">$file" or die "Failed to open `$file': $!"; local $\ = "\n"; print $fh 'P1'; print $fh "# $file"; print $fh $self->get(-width ); print $fh $self->get(-height ); print $fh $self->as_string; $self->set(-setch => $setch,-unsetch => $unsetch ); } 1;