Imagick::convolveImage

(PECL imagick 2, PECL imagick 3)

Imagick::convolveImage — Applies a custom convolution kernel to the image

Description

public Imagick::convolveImage(array $kernel, int $channel = Imagick::CHANNEL_DEFAULT): bool

Applies a custom convolution kernel to the image.

Parameters

kernel: The convolution kernel
channel: Provide any channel constant that is valid for your channel mode. To apply to more than one channel, combine channeltype constants using bitwise operators. Refer to this list of channel constants.

Return Values

Returns true on success.

Errors/Exceptions

Throws ImagickException on error.

Examples

Example #1 Imagick::convolveImage()

<?php
function convolveImage($imagePath, $bias, $kernelMatrix) {
    $imagick = new \Imagick(realpath($imagePath));    
    //$edgeFindingKernel = [-1, -1, -1, -1, 8, -1, -1, -1, -1,];
    $imagick->setImageBias($bias * \Imagick::getQuantum());
    $imagick->convolveImage($kernelMatrix);
    header("Content-Type: image/jpg");
    echo $imagick->getImageBlob();
}

?>

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User Contributed Notes 2 notes

down

ahmed at zigzapps dot com ¶

5 years ago

The provided example is wrong. Here's a correct sample:

$matrix = [[1,-1,1],[-1,1,-1],[1,-1,1]];
$kernel = \ImagickKernel::fromMatrix($matrix); 

$imagick = new Imagick();
$imagick->readimage($file.'/z.png');
$imagick->convolveImage ($kernel);
$imagick->writeimage('convolve.png');
$imagick->clear();
$imagick->destroy();

down

-1

peter at musicalsaw dot com ¶

11 years ago

Example of convolveImage:

<?php
// run an edge detection filter on an image
$image = new imagick( "diana.png" ); 
$edgeArray = array(-1,-1,-1,-1,8,-1,-1,-1,-1);
$image->convolveImage ($edgeArray);
$image->thresholdImage(1);
header('Content-type: image/png');
echo $image;
?>

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