(PECL imagick 2, PECL imagick 3)
Imagick::posterizeImage — Reduces the image to a limited number of color level
$levels
, bool $dither
) : boolReduces the image to a limited number of color level.
levels
dither
成功时返回 true。
Example #1 Imagick::posterizeImage()
<?php
function posterizeImage($imagePath, $posterizeType, $numberLevels) {
$imagick = new \Imagick(realpath($imagePath));
$imagick->posterizeImage($numberLevels, $posterizeType);
$imagick->setImageFormat('png');
header("Content-Type: image/png");
echo $imagick->getImageBlob();
}
posterizeImage($imagePath, \Imagick::DITHERMETHOD_RIEMERSMA, 8);
?>
At PHP 7.x before
$im->posterizeimage(2, FALSE);
do
$im->setImageType(imagick::IMGTYPE_COLORSEPARATION);
on PHP 5.x working without setImageType well.
Example:
$im = new Imagick();
$r = $im->readImageBlob($label);
if (!$r) {
return FALSE;
}
$im->setImageType(imagick::IMGTYPE_COLORSEPARATION);
$im->posterizeimage(2, 0);
$bmp = $im->getImageBlob();