php gd扩展库对图像高斯模糊处理

<?php
require_once 'RGB.php'; //这里请看另一个 "PHP实现色彩空间转换"
/**
* 图像信息处理
* @author shizhuolin
*/
class Image {
/**
* 位图资源
* @var resource
*/
protected $_image;
/**
* 使用指定文件构造图像操作实例
* @param string $filename
*/
public function __construct($filename=null) {
if ($filename)
$this->open($filename);
}
/**
* 读取指定文件明的图像
* @param string $filename
* @return Image
*/
public function open($filename) {
$handle = fopen($filename, "rb");
$contents = stream_get_contents($handle);
fclose($handle);
$image = imagecreatefromstring($contents);
$width = imagesx($image);
$height = imagesy($image);
$truecolorimage = imagecreatetruecolor($width, $height);
imagefilledrectangle($truecolorimage, 0, 0, $width, $height, 0xFFFFFF);
imagecopyresampled($truecolorimage, $image, 0, 0, 0, 0, $width, $height, $width, $height);
imagedestroy($image);
$this->setImage($truecolorimage);
return $this;
}
/**
* 读取指定资源的图像
* @param resource $image
* @return Image
*/
public function load($image) {
$width = imagesx($image);
$height = imagesy($image);
$truecolorimage = imagecreatetruecolor($width, $height);
imagefilledrectangle($truecolorimage, 0, 0, $width, $height, 0xFFFFFF);
imagecopyresampled($truecolorimage, $image, 0, 0, 0, 0, $width, $height, $width, $height);
if ($this->getImage()) {
imagedestroy($this->getImage());
}
$this->setImage($truecolorimage);
return $this;
}
/**
* 设置内部图像资源描述符
* @param resource $image
*/
protected function setImage($image) {
$this->_image = $image;
}
/**
* 获取内部操作图像资源
* @return resource
*/
public function getImage() {
return $this->_image;
}
/**
* 获取图像宽度
* @return int
*/
public function getWidth() {
return imagesx($this->getImage());
}
/**
* 获取图像高度
* @return int
*/
public function getHeight() {
return imagesy($this->getImage());
}
/**
* 获取指定坐标像素颜色
* @param type $x
* @param type $y
* @return type
*/
public function getColorAt($x, $y) {
$rgb = imageColorAt($this->getImage(), $x, $y);
$r = ($rgb >> 16) & 0xFF;
$g = ($rgb >> 8) & 0xFF;
$b = $rgb & 0xFF;
return array('red' => $r, 'green' => $g, 'blue' => $b);
}
/**
* 高斯模糊(单纬度二次模糊)
* @param float $radius 半径
*/
public function gaussianBlur($radius=1.0) {
$width = $this->getWidth();
$height = $this->getHeight();
$sigma = $radius / 3;
$sigma2 = 2 * pow($sigma, 2);
$matrix = array();
$newimage = imagecreatetruecolor($width, $height);
/* 生成高斯矩阵(单纬度矩阵) */
for ($x = -$radius; $x <= $radius; $x++) {
$x2 = pow($x, 2) + pow($x, 2);
$matrix[] = exp(-$x2 / $sigma2) / ($sigma2 * M_PI);
}
/* 构建模糊图像 */
for ($y = 0; $y < $height; $y++) {
for ($x = 0; $x < $width; $x++) {
$bright = $red = $green = $blue = 0;
/* 垂直模糊 */
for ($yy = -$radius; $yy <= $radius; $yy++) {
$yyy = $y + $yy;
if ($yyy >= 0 && $yyy < $height) {
$weight = $matrix[$yy + $radius];
$bright += $weight;
$color = $this->getColorAt($x, $yyy);
$red += ($color['red'] * $weight);
$green += ($color['green'] * $weight);
$blue += ($color['blue'] * $weight);
}
}
/* 水平模糊 */
for ($xx = -$radius; $xx <= $radius; $xx++) {
$xxx = $x + $xx;
if ($xxx >= 0 && $xxx < $width && $xx != 0) {
$weight = $matrix[$xx + $radius];
$bright+=$weight;
$color = $this->getColorAt($xxx, $y);
$red += ($color['red'] * $weight);
$green += ($color['green'] * $weight);
$blue += ($color['blue'] * $weight);
}
}
$z = 1 / $bright;
imagesetpixel($newimage, $x, $y, ($red * $z << 16) | ($green * $z << 8) | $blue * $z);
}
}
imagedestroy($this->getImage());
$this->setImage($newimage);
}
/**
* 析构 销毁图像占用内存
*/
public function __destruct() {
if ($this->getImage()) {
imagedestroy($this->getImage());
}
}
}

<?php
require_once 'Image.php';
$image = new Image("http://www.yuju100.com/images/1220676617582974754.jpg");
$image->gaussianBlur(10);
header("Content-type: image/png");
imagepng($image->getImage());