You want to check wether an image has an alpha channel? But you have no control which Imagick Version is used?
Background:
Method available since ImageMagick 6.4.0
Method returns boolean instead of int since 6.9.x
Example:
$image= new Imagick();
$image->readImage($source_file);
$imageHasAlphaChannel = (method_exists($image, 'getImageAlphaChannel') && ($document->getImageAlphaChannel() === \Imagick::ALPHACHANNEL_ACTIVATE || $document->getImageAlphaChannel() === true));
Imagick::getImageAlphaChannel
(PECL imagick 2 >= 2.3.0, PECL imagick 3)
Imagick::getImageAlphaChannel — 检查图像是否有 alpha 通道
参数
此函数没有参数。
返回值
如果图像具有 alpha 通道值，则返回 true，否则返回 false，即图像是 RGB 而不是 RGBA 或 CMYK 而不是 CMYKA。
错误／异常
错误时抛出 ImagickException。
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User Contributed Notes 1 note
phroggar ¶
2 years ago
