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Imagick::blackThresholdImage

(PECL imagick 2, PECL imagick 3)

Imagick::blackThresholdImageForces all pixels below the threshold into black

Descrição

public Imagick::blackThresholdImage(mixed $threshold): bool

Is like Imagick::thresholdImage() but forces all pixels below the threshold into black while leaving all pixels above the threshold unchanged.

Parâmetros

threshold

The threshold below which everything turns black

Valor Retornado

Retorna true em caso de sucesso.

Registro de Alterações

Versão Descrição
PECL imagick 2.1.0 Now allows a string representing the color as a parameter. Previous versions allow only an ImagickPixel object.

Exemplos

Exemplo #1 Imagick::blackThresholdImage()

<?php
function blackThresholdImage($imagePath, $thresholdColor) {
$imagick = new \Imagick(realpath($imagePath));
$imagick->blackthresholdimage($thresholdColor);
header("Content-Type: image/jpg");
echo
$imagick->getImageBlob();
}

?>

add a note

User Contributed Notes 2 notes

up
4
Iddles
12 years ago
You need to pass this function a colour:

<?php

$img
->blackThresholdImage( "#FFFFFF" );

?>

E.g. this blackens any pixel which isn't pure white.
up
1
elmer at web-axis dot net
15 years ago
Here's a example of this function:

<?php
$img
= new Imagick();
$img->readImage($image_file_name);
$img->blackThresholdImage('grey');
$img->writeImage($thumb_file_name);
$img->clear();
$img->destroy();
?>
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