Image::Thumbnail

NAME
SYNOPSIS
DESCRIPTION
PREREQUISITES
CONSTRUCTOR new
- REQUIRED PARAMETERS
- OPTIONAL PARAMETERS

NAME

Image::Thumbnail - Simple thumbnails with various Perl libraries

SYNOPSIS

	use Image::Thumbnail 0.65;

	# Create a thumbnail from 'test.jpg' as 'test_t.jpg'
	# using ImageMagick, Imager, GD or Image::Epeg.
	my $t = new Image::Thumbnail(
		size       => 55,
		create     => 1,
		input      => 'test.jpg',
		outputpath => 'test_t.jpg',
	);

	# With Image Magick
	my $t = new Image::Thumbnail(
		size       => "55x75",
		create     => 1,
		module	   => "Image::Magick",
		input      => $imageObject,
		outputpath => 'test_t.jpg',
	);

	# Create a thumbnail from 'test.jpg' as 'test_t.jpg'
	# using GD.
	my $t = new Image::Thumbnail(
		module     => 'GD',
		size       => 55,
		create     => 1,
		input      => 'test.jpg',
		outputpath => 'test_t.jpg',
	);

	# Create a thumbnail from 'test.jpg' as 'test_t.jpg'
	# using Imager.
	my $t = new Image::Thumbnail(
		module     => 'Imager',
		size       => 55,
		create     => 1,
		input      => 'test.jpg',
		outputpath => 'test_t.jpg',
	);

	# Create a thumbnail as 'test_t.jpg' from an ImageMagick object
	# using ImageMagick, or GD.
	my $t = new Image::Thumbnail(
		size       => "55x25",
		create     => 1,
		input      => $my_image_magick_object,
		outputpath => 'test_t.jpg',
	);

	# Create four more of ever-larger sizes
	for (1..4){
		$t->{size} = 55+(10*$_);
		$t->create;
	}

	exit;

DESCRIPTION

This module was created to answer the FAQ, 'How do I simply create a thumbnail with pearl?' (sic). It allows you to easily make thumbnail images from files, objects or (in most cases) 'blobs', using either the ImageMagick, Image::Epeg, Imager or GD libraries.

Thumbnails created can either be saved as image files or accessed as objects via the object field: see /create.

In the experience of the author, thumbnails are created fastest with direct use of the Image::Epeg module.

PREREQUISITES

One of Image::Magick, Imager, Image::Epeg, or GD.

CONSTRUCTOR new

Parameters are supplied as a hash or hash-like list of name/value pairs: See the /SYNOPSIS.

REQUIRED PARAMETERS

size

The size you with the longest side of the thumbnail to be. This may be provided as a single integer, or as an ImageMagick-style 'geometry' such as 100x120.

input

You must the input parameter as one of:

Input file path: A scalar that is an absolute path to an image to use as the source file.
Object: An object-reference created by your chosen package. Naturally you can't supply this field if you haven't specified a module field (see above).
Blob: A reference to a scalar that is the raw binary image data, perhaps drawn from a database BLOB column, perhaps from a file.

The formerly required input fields should be considered depricated, and although they will be kept in the API for this release, they will eventually be removed.

OPTIONAL PARAMETERS

module ( GD | Image::Magick | Imager | Image::JPEG)

If you wish to use a specific module, place its name here. You must have the module you require already installed!

Supplying no name will allow ImageMagick, then Imager to be tried before GD.

create

Put any value in this field if you wish the constructor to call the create method automatically before returning.

inputtype, outputtype

If you are using GD, you can explicitly set the input and output formats for the image file, provided you use a string that can be evaluated to a GD-supported image format (see GD).

Default behaviour is to attempt to ascertin the file type and to create the thumbnail in the same format. If the type cannot be defined (you are using GD, have supplied the object field and not the outputtype field) then the output file format defaults to jpeg.

depth

Sets colour depth in ImageMagick - AFAIK GD only supports 8-bit.

The ImageMagick manpage (see http://www.imagemagick.org/www/ImageMagick.html#opti). says:

density

ImageMagick only: sets the pixel density. Must be a valid ImageMagick 'geometry' value (that is, two numbers giving the x and y dimensions, delimited by a lower-case x. Default value is 96x96.

quality

ImageMagick/Imager only: an integer from 1 to 100 to specify the thumbnail quality. Defaults to 50.

attr

If you are using ImageMagick, this field should contain a hash of ImageMagick attributes to pass to the ImageMagick Set command when the thumbnail is created. Any errors these may generate are not yet caught.

CHAT

Put any value in this field for real-time process info.

PARAMETERS SET

x,y: The dimension of the thumbnail produced.

ERRORS

As of version 0.4, any errors are stored in the fields error, warnings in warning.

Any errors will be printed to STDOUT. If they completely prevent processing, they will be fatal (croaked). If partial processing has taken place by the explicit or implicit calling of the create method, then the field of the same name will have value.

Depending on how far processing has proceded, other fields may have useful values: the module field will contain the name of the module used; the object field may contain an object of the module used; the thumb field may contain a thumbnail image.

METHOD create

Creates a thumbnail using the supplied object. This method is called automatically if you construct with the create field flagged.

Sets the following fields:

module: Will contain the name of the module used (set by this module if not by the user);
object: Will contain an instance of the module used;
thumb: Will contain the thumbnail image.

Returns c<undef> on failure.

EXPORT

None.

CHANGES

Please see the file CHANGES included with the distribution.

AUTHOR

Lee Goddard <cpan-at-leegoddard-dot-net>

Thanks to Sam Tregar, Himmy and Chris Laco.