---
name: "Imager::Transform"
section: "3pm"
platform: "linux"
package: "libimager-perl"
version: "1.027+dfsg-1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/Imager::Transform"
---

# Imager::Transform(3pm)

## NAME

```
  Imager::Transform - a library of register machine image transformations
```

## SYNOPSIS

```
  # get a list of transformations
  my @funcs = Imager::Transform->list;
  # create a transformation object
  my $tran = Imager::Transform->new($name);
  # describe it
  print $tran->describe;
  # a list of constant names
  my @constants = $tran->constants;
  # information about some of the constants
  my @info = $tran->constants(@constants);
```

## DESCRIPTION

This module provides a library of transformations that use the Imager **transform2()** function.

The aim is to provide a place to collect these transformations.

At some point there might be an interface to add new functions, but there's not a whole lot of point to that.

The interface is a little sparse as yet.

## METHODS

- my @names = Imager::Transform-\>list

  Returns a list of the transformations.

- my $desc = Imager::Transform-\>describe($name);

  - my $desc = $tran-\>**describe()**

  Describes a transformation specified either by name (as a class method) or by reference (as an instance method).

  The class method returns undef if there is no such transformation.

- my $tran = Imager::Transform-\>new($name)

  Create a new transformation object.  Returns undef if there is no such transformation.

- my @inputs = $tran-\>inputs;

  - my $inputs = $tran-\>inputs;

  Returns a list of input image descriptions, or the number of them, depending on content.

  The list contains hash references, which current contain only one member, `"desc"`, a description of the use of the input image.

- $tran-\>constants

  Returns a list of names of constants that can be set for the transformation.

- $tran-\>constants($name, $name, ...)

  Returns a hashref for each named constant, which contains the default in key `"default"` and a description in key `"desc"`.

- my $out = $tran-\>transform(\\%opts, \\%constants, @imgs)

  Perform the image transformation.

  Returns the new image on success, or undef on failure, in which case you can use `$tran`-\>errstr to get an error message.

- $tran-\>errstr

  The error message, if any from the last image transformation.

## BUGS

Needs more transformations.

## SEE ALSO

**Imager**(3), *transform.perl*

## AUTHOR

Tony Cook \<tonyc@cpan.org\>