imageconvolution
(PHP 5 >= 5.1.0, PHP 7)
imageconvolution — Apply a 3x3 convolution matrix, using coefficient and offset
Description
$image
, array $matrix
, float $div
, float $offset
) : boolApplies a convolution matrix on the image, using the given coefficient and offset.
Parameters
-
image -
An image resource, returned by one of the image creation functions, such as imagecreatetruecolor().
-
matrix -
A 3x3 matrix: an array of three arrays of three floats.
-
div -
The divisor of the result of the convolution, used for normalization.
-
offset -
Color offset.
Examples
Example #1 Embossing the PHP.net logo
<?php
$image = imagecreatefromgif('http://www.php.net/images/php.gif');
$emboss = array(array(2, 0, 0), array(0, -1, 0), array(0, 0, -1));
imageconvolution($image, $emboss, 1, 127);
header('Content-Type: image/png');
imagepng($image, null, 9);
?>
The above example will output:
Example #2 Gaussian blur
<?php
$image = imagecreatetruecolor(180,40);
// Writes the text and apply a gaussian blur on the image
imagestring($image, 5, 10, 8, 'Gaussian Blur Text', 0x00ff00);
$gaussian = array(array(1.0, 2.0, 1.0), array(2.0, 4.0, 2.0), array(1.0, 2.0, 1.0));
imageconvolution($image, $gaussian, 16, 0);
// Rewrites the text for comparison
imagestring($image, 5, 10, 18, 'Gaussian Blur Text', 0x00ff00);
header('Content-Type: image/png');
imagepng($image, null, 9);
?>
The above example will output:
English translation
You have asked to visit this site in English. For now, only the interface is translated, but not all the content yet.If you want to help me in translations, your contribution is welcome. All you need to do is register on the site, and send me a message asking me to add you to the group of translators, which will give you the opportunity to translate the pages you want. A link at the bottom of each translated page indicates that you are the translator, and has a link to your profile.
Thank you in advance.
Document created the 30/01/2003, last modified the 26/10/2018
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References
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