JavaScript Editor Javascript debugger     Website design 

imageconvolution

Apply a 3x3 convolution matrix, using coefficient and offset (PHP 5 >= 5.1.0)
bool imageconvolution ( resource image, array matrix, float div, float offset )

Applies 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

Return Values

Returns TRUE on success or FALSE on failure.

Examples

Example 994. 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 995. 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:


Notes

Note:

This function is only available if PHP is compiled with the bundled version of the GD library.