Imagick::unsharpMaskImage()

(PECL imagick 2.0.0)

Sharpens an image

说明

Imagick::unsharpMaskImage(float $radius,float $sigma,float $amount,float $threshold[,int $channel= Imagick::CHANNEL_DEFAULT]): bool

Sharpens an image. We convolve the image with a Gaussian operator of the given radius and standard deviation(sigma). For reasonable results, radius should be larger than sigma. Use a radius of 0 and Imagick::UnsharpMaskImage()selects a suitable radius for you.

参数

$radius

$sigma

$amount

$threshold

$channel

返回值

成功时返回TRUE。

错误／异常

错误时抛出 ImagickException。

范例

Example #1 Imagick::unsharpMaskImage()

<?php
function unsharpMaskImage($imagePath, $radius, $sigma, $amount, $unsharpThreshold) {
    $imagick = new \Imagick(realpath($imagePath));
    $imagick->unsharpMaskImage($radius, $sigma, $amount, $unsharpThreshold);
    header("Content-Type: image/jpg");
    echo $imagick->getImageBlob();
}
?>

Prepare photo for web
<?php
$im = new Imagick($SrcFile);
$im->resizeImage ( $Width, $Height , Imagick::FILTER_QUADRATIC , 1 );
    
$im->normalizeImage();
$im->unsharpMaskImage(0 , 0.5 , 1 , 0.05);
    
$im->setImageFormat( "jpg" );
$im->setCompressionQuality(75);
$im->writeImage( $OutFile );
    
$im->removeImage();
?>