IMAGECONVOLUTION(3)							 1						       IMAGECONVOLUTION(3)

imageconvolution - Apply a 3x3 convolution matrix, using coefficient and offset

SYNOPSIS
bool imageconvolution (resource $image, array $matrix, float $div, float $offset) DESCRIPTION
Applies a convolution matrix on the image, using the given coefficient and offset. PARAMETERS
o $ image -An image resource, returned by one of the image creation functions, such as imagecreatetruecolor(3). o $matrix - A 3x3 matrix: an array of three arrays of three floats. o $div - The divisor of the result of the convolution, used for normalization. o $offset - Color offset. RETURN VALUES
Returns TRUE on success or FALSE on failure. 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:[NOT DISPLAYABLE MEDIA]Output of example : Embossing the PHP.net logo 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:[NOT DISPLAYABLE MEDIA]Output of example : Gaussian blur NOTES
Note This function is only available if PHP is compiled with the bundled version of the GD library. SEE ALSO
imagefilter(3). PHP Documentation Group IMAGECONVOLUTION(3)