# Imagick::functionImage

(No version information available, might only be in Git)

Imagick::functionImage — Applies a function on the image

### Description

public Imagick::functionImage ( int `$function` , array `$arguments` [, int `$channel` = Imagick::CHANNEL_DEFAULT ] ) : bool

Applies an arithmetic, relational, or logical expression to a pseudo image.

See also » ImageMagick v6 Examples - Image Transformations — Function, Multi-Argument Evaluate

This method is available if Imagick has been compiled against ImageMagick version 6.4.9 or newer.

### Parameters

`function`

  Refer to this list of function constants

`arguments`

  Array of arguments to pass to this function.

### Return Values

Returns `TRUE` on success.

### Errors/Exceptions

Throws ImagickException on error.

### Examples

Example #1 Create a sinusoidal gradient

`<?php
$imagick = new Imagick();
$imagick->newPseudoImage(200, 200, 'gradient:black-white');
$arguments = array(3, -90);
$imagick->functionImage(Imagick::FUNCTION_SINUSOID, $arguments);
header("Content-Type: image/png");
$imagick->setImageFormat("png");
echo $imagick->getImageBlob();
?>`

The above example will output something similar to:

Example #2 Create a gradient from the polynomial (4x^2 - 4x + 1)

`<?php
$imagick = new Imagick();
$imagick->newPseudoImage(200, 200, 'gradient:black-white');
$arguments = array(4, -4, 1);
$imagick->functionImage(Imagick::FUNCTION_POLYNOMIAL, $arguments);
header("Content-Type: image/png");
$imagick->setimageformat("png");
echo $imagick->getImageBlob();
?>`

The above example will output something similar to:

Example #3 Create a complex gradient from the polynomial (4x^2 - 4x^2 + 1) modulated by a sinusoidal gradient

`<?php
$imagick1 = new Imagick();
$imagick1->newPseudoImage(200, 200, 'gradient:black-white');
$arguments = array(9, -90);
$imagick1->functionImage(Imagick::FUNCTION_SINUSOID, $arguments);
$imagick2 = new Imagick();
$imagick2->newPseudoImage(200, 200, 'gradient:black-white');
$arguments = array(0.5, 0);
$imagick2->functionImage(Imagick::FUNCTION_SINUSOID, $arguments);
$imagick1->compositeimage($imagick2, Imagick::COMPOSITE_MULTIPLY, 0, 0);
header("Content-Type: image/png");
$imagick1->setImageFormat("png");
echo $imagick1->getImageBlob();
?>`

The above example will output something similar to: