PDL examples?

[impossiblerobot]

In response to this node, fglock suggested using the PDL module to resize 2D graphics. Unfortunately, circumstances prevented fglock from providing an example of how this might be done, so I decided to make a request to the Monastery in general.

If anyone has any experience with the Perl Data Language, and is willing to share some code, I would be interested in seeing how useful this (seemingly complex) collection of modules is.

Although I'm primarily interested at this point in 2D graphics transformations, I would also be interested in seeing other practical uses you've made of PDL (since most of the examples I've seen seem fairly obscure).

Impossible Robot

[Zaxo]

The Wolf Book, chapter 7, has a whole series of examples using PDL to represent and modify an image.

I have used PDL::FFT for signal processing/generation chores. To use PDL, just feed it an array reference in the constructor. An example of mine is at Re: Manipulating Audio Data in Perl.

Modifying an image file would involve rewriting the image file's headers as well as the data munging itself.

After Compline,
Zaxo

[fglock]

this is a simple "rescale to 256x256" program. (there are too many "use" statements here - this was cut from a larger program).

#! /bin/perl
use PDL;
use PDL::FFT;
use PDL::IO::Pic;
use PDL::Image2D;
use PDL::ImageRGB;
use PDL::ImageND;
use PDL::Primitive;
use PDL::Slices;

  $real = PDL->rpic('image.pgm');    # read image
  $display = zeroes(256,256);        # new empty image
  PDL::rescale2d($real, $display);   # scale into empty image
  $display->wpic("test.tif");       # done

update:Zaxo: PDL::IO::Pic takes care of image headers, compression, etc. for you.