NAME

Image::Signature - Deriving signatures of images

SYNOPSIS

  use Image::Signature;


  # initiation from the ground
  $sig_obj = new Image::Signature("pic.jpg");

  # initiation from an image-magick object
  $sig_obj = new Image::Signature $image_object;

  # calculation of signature
  $sig_object_A->signature();

  # comparison of two signature
  $sig_object_A->compare($sig_object_B);

DESCRIPTION

Image signature is something that can be capable of describing properties of an image without knowing the entire picture. It is analogous to index of texts. Signatures are produced using various algorithms, including color histograms, texture properties, local and global attributes, etc. This module is aimed at being able to implement some practical, general-purpose, and easy-to-implement algorithms for producing signatures. With signatures, one can develop further applications, such as image retrieval systems. Fortunately, with the ImageMagick backend, multiple formats of images are supported.

Since I'm just a newbie in image processing, currently, only color histogram and gray-level moments are implemented, and the modules are poorly documented. The code is entirely written in PERL, and so it may be inevitably slow. The module will be expanded and upgraded in the future with the growth of my knowledge if it grows.

METHODS

new

The argument can be an image file or an ImageMagick object.

 $sig_obj = new Image::Signature $arg;

signature

Derives image signature.

The current methods available are color histograms and gray-level moment.

color_histogram

 $sig_obj->color_histogram;

gray_moment

 $sig_obj->gray_moment;

compare

Compares the similarity between two image objects.

 $sig_objA->compare($sig_objB);

SEE ALSO

GD, Image::Magick

BUGS AND TODOs

Must be many. Please report them to me.

COPYRIGHT

xern <xern@cpan.org>

This module is free software; you can redistribute it or modify it under the same terms as Perl itself.