Imagick::evaluateImage
(PECL imagick 2, PECL imagick 3)
Imagick::evaluateImage — Applies an expression to an image
Descrizione
public Imagick::evaluateImage
( int $op
, float $constant
[, int $channel
= Imagick::CHANNEL_DEFAULT
] ) : bool
Elenco dei parametri
-
op
-
The evaluation operator
-
constant
-
The value of the operator
-
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.
Esempi
Example #1 Using Imagick::evaluateImage()
Using evaluateImage to reduce opacity in an image.
<?php
// Create new object with the image
$im = new Imagick('example-alpha.png');
// Reduce the alpha by 50%
$im->evaluateImage(Imagick::EVALUATE_DIVIDE, 2, Imagick::CHANNEL_ALPHA);
// Output the image
header("Content-Type: image/png");
echo $im;
?>
Valori restituiti
Restituisce true
in caso di successo.
Errori/Eccezioni
Lancia una ImagickException in caso di errore.