imageconvolution
(PHP 5 >= 5.1.0, PHP 7)
imageconvolution — 用系数 div 和 offset 申请一个 3x3 的卷积矩阵
说明
bool imageconvolution
( resource
$image
, array $matrix
, float $div
, float $offset
)Applies a convolution matrix on the image, using the given coefficient and offset.
参数
-
image -
由图象创建函数(例如imagecreatetruecolor())返回的图象资源。
-
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.
返回值
成功时返回 TRUE， 或者在失败时返回 FALSE。
范例
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);
?>
以上例程会输出：
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);
?>
以上例程会输出：
注释
Note: 此函数仅在与 GD 库捆绑编译的 PHP 版本中可用。