PHP实现生成模糊图片的方法示例

<?php
class image_blur{
/**
  * 图片高斯模糊（适用于png/jpg/gif格式）
  * @param $srcimg 原图片
  * @param $savepath 保存路径
  * @param $savename 保存名字
  * @param $positon 模糊程度
  *
  *基于martijn frazer代码的扩充， 感谢 martijn frazer
  */
 public function gaussian_blur($srcimg,$savepath=null,$savename=null,$blurfactor=3){
  $gdimageresource=$this->image_create_from_ext($srcimg);
  $srcimgobj=$this->blur($gdimageresource,$blurfactor);
  $temp = pathinfo($srcimg);
  $name = $temp['basename'];
  $path = $temp['dirname'];
  $exte = $temp['extension'];
  $savename = $savename ? $savename : $name;
  $savepath = $savepath ? $savepath : $path;
  $savefile = $savepath .'/'. $savename;
  $srcinfo = @getimagesize($srcimg);
  switch ($srcinfo[2]) {
   case 1: imagegif($srcimgobj, $savefile); break;
   case 2: imagejpeg($srcimgobj, $savefile); break;
   case 3: imagepng($srcimgobj, $savefile); break;
   default: return '保存失败'; //保存失败
  }
  return $savefile;
  imagedestroy($srcimgobj);
 }
 /**
 * strong blur
 *
 * @param $gdimageresource 图片资源
 * @param $blurfactor   可选择的模糊程度
 * 可选择的模糊程度 0使用 3默认 超过5时 极其模糊
 * @return gd image 图片资源类型
 * @author martijn frazer, idea based on http://*.com/a/20264482
 */
 private function blur($gdimageresource, $blurfactor = 3)
 {
  // blurfactor has to be an integer
  $blurfactor = round($blurfactor);
  $originalwidth = imagesx($gdimageresource);
  $originalheight = imagesy($gdimageresource);
  $smallestwidth = ceil($originalwidth * pow(0.5, $blurfactor));
  $smallestheight = ceil($originalheight * pow(0.5, $blurfactor));
  // for the first run, the previous image is the original input
  $previmage = $gdimageresource;
  $prevwidth = $originalwidth;
  $prevheight = $originalheight;
  // scale way down and gradually scale back up, blurring all the way
  for($i = 0; $i < $blurfactor; $i += 1)
  {
   // determine dimensions of next image
   $nextwidth = $smallestwidth * pow(2, $i);
   $nextheight = $smallestheight * pow(2, $i);
   // resize previous image to next size
   $nextimage = imagecreatetruecolor($nextwidth, $nextheight);
   imagecopyresized($nextimage, $previmage, 0, 0, 0, 0,
    $nextwidth, $nextheight, $prevwidth, $prevheight);
   // apply blur filter
   imagefilter($nextimage, img_filter_gaussian_blur);
   // now the new image becomes the previous image for the next step
   $previmage = $nextimage;
   $prevwidth = $nextwidth;
   $prevheight = $nextheight;
  }
  // scale back to original size and blur one more time
  imagecopyresized($gdimageresource, $nextimage,
  0, 0, 0, 0, $originalwidth, $originalheight, $nextwidth, $nextheight);
  imagefilter($gdimageresource, img_filter_gaussian_blur);
  // clean up
  imagedestroy($previmage);
  // return result
  return $gdimageresource;
 }
 private function image_create_from_ext($imgfile)
 {
  $info = getimagesize($imgfile);
  $im = null;
  switch ($info[2]) {
  case 1: $im=imagecreatefromgif($imgfile); break;
  case 2: $im=imagecreatefromjpeg($imgfile); break;
  case 3: $im=imagecreatefrompng($imgfile); break;
  }
  return $im;
 }
}
$image_blur = new image_blur();
$image_blur->gaussian_blur("./1.jpg",null,null,3);
?>