Applies a function on the image

# Imagick::functionImage

(PECL imagick 2 >= 2.3.0, PECL imagick 3)

Imagick::functionImage — Applies a function on the image

### 说明

public function 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

此方法在Imagick基于ImageMagick 6.4.9以上版本编译时可用。

### 参数

`function`

  Refer to this list of function constants

`arguments`

  Array of arguments to pass to this function.

### 返回值

成功时返回 `true`。

### 错误／异常

错误时抛出 ImagickException。

### 示例

示例 #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();
    ?>

以上示例的输出类似于：

示例 #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();
    ?>

以上示例的输出类似于：

示例 #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();
    ?>

以上示例的输出类似于：

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