Imagick::blackThresholdImage

(PECL imagick 2.0.0)

Imagick::blackThresholdImage — Forces all pixels below the threshold into black

Descrição

bool Imagick::blackThresholdImage ( mixed $threshold )

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 sucesso.

Histórico

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

add a note User Contributed Notes Imagick::blackThresholdImage

Iddles 06-Jul-2011 05:35


You need to pass this function a colour:



<?php



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



?>



E.g. this blackens any pixel which isn't pure white.

elmer at web-axis dot net 30-Nov-2008 03:33


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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