Imagick::adaptiveThresholdImage

(PECL imagick 2.0.0)

Imagick::adaptiveThresholdImage — Selects a threshold for each pixel based on a range of intensity

说明

bool Imagick::adaptiveThresholdImage ( int $width , int $height , int $offset )

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.

参数

width: Width of the local neighborhood.
height: Height of the local neighborhood.
offset: The mean offset

返回值

成功时返回 TRUE。

范例

Example #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();
}

?>