(PECL imagick 2, PECL imagick 3)
Imagick::adaptiveThresholdImage — Selects a threshold for each pixel based on a range of intensity
Selects an individual threshold for each pixel based on the range of intensity values in its local neighborhood. This allows for thresholding of an image whose global intensity histogram doesn't contain distinctive peaks.
widthWidth of the local neighborhood.
heightHeight of the local neighborhood.
offsetThe mean offset
成功时返回 true。
示例 #1 Imagick::adaptiveThresholdImage()
<?php
function adaptiveThresholdImage($imagePath, $width, $height, $adaptiveOffset) {
$imagick = new \Imagick(realpath($imagePath));
$adaptiveOffsetQuantum = intval($adaptiveOffset * \Imagick::getQuantum());
$imagick->adaptiveThresholdImage($width, $height, $adaptiveOffsetQuantum);
header("Content-Type: image/jpg");
echo $imagick->getImageBlob();
}
?>