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(PECL imagick 2.0.0)
Imagick::blackThresholdImage — Forces all pixels below the threshold into black
$threshold
)Is like Imagick::thresholdImage() but forces all pixels below the threshold into black while leaving all pixels above the threshold unchanged.
threshold
The threshold below which everything turns black
成功时返回 TRUE
。
版本 | 说明 |
---|---|
2.1.0 | Now allows a string representing the color as a parameter. Previous versions allow only an ImagickPixel object. |
Example #1 Imagick::blackThresholdImage()
<?php
function blackThresholdImage ( $imagePath , $thresholdColor ) {
$imagick = new \ Imagick ( realpath ( $imagePath ));
$imagick -> blackthresholdimage ( $thresholdColor );
header ( "Content-Type: image/jpg" );
echo $imagick -> getImageBlob ();
}
?>
[#1] Iddles [2011-07-06 17:35:24]
You need to pass this function a colour:
<?php
$img->blackThresholdImage( "#FFFFFF" );
?>
E.g. this blackens any pixel which isn't pure white.
[#2] elmer at web-axis dot net [2008-11-30 15:33:54]
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();
?>