Imagick::fxImage()

(PECL imagick 2.0.0)

Evaluate expression for each pixel in the image

说明

Imagick::fxImage(string $expression[,int $channel= Imagick::CHANNEL_DEFAULT]): Imagick

Evaluate expression for each pixel in the image. Consult » The Fx Special Effects Image Operator for more information.

参数

$expression: The expression.
$channel: Provide any channel constant that is valid for your channel mode. To apply to more than one channel, combine channeltype constants using bitwise operators. Refer to this list of channel constants.

返回值

成功时返回TRUE。

错误／异常

错误时抛出 ImagickException。

范例

Example #1 Imagick::fxImage()

<?php
function fxImage() {
    $imagick = new \Imagick();
    $imagick->newPseudoImage(200, 200, "xc:white");
    $fx = 'xx=i-w/2; yy=j-h/2; rr=hypot(xx,yy); (.5-rr/140)*1.2+.5';
    $fxImage = $imagick->fxImage($fx);
    header("Content-Type: image/png");
    $fxImage->setimageformat('png');
    echo $fxImage->getImageBlob();
}
?>

Beware that fxImage return value's type is a new object(Imagick), opposing the current documentation (boolean). Therefore it does not affect the caller object. Example:
<?php
      $canvas = new Imagick();
      $canvas->newImage(256, 256, "white", "jpg");
      $gradient = new Imagick();
      $gradient->newPseudoImage(256, 256, "gradient:white-black");
      $canvas->compositeImage( $gradient, imagick::COMPOSITE_OVER, 0, 0 );
      $canvas->rotateImage(new ImagickPixel(), 90);
      /*instead of just $canvas->fxImage("floor(s*10+0.5)/10"); we must store fxImage()'s result*/
      $canvas= $canvas->fxImage("floor(s*10+0.5)/10");
      header( "Content-Type: image/jpg" );
      echo $canvas; 
?>