Nginx+PHP 动态实时生成不同尺寸图片
原来图片服务器采用Windows .net架构，鉴于需求需要生成各种尺寸图片。
流程说明:
用户从Nginx请求对应的图片,判断是否存在_200x300的对应参数，如果没有就直接请求到对应目录的原图，否则继续判断是否在本地已经生成了对应的缓存图片，如果存在返回已经生成过的定制尺寸图片，否则请求PHP动态生成。
Nginx部分配置:
server {
listen 80;
server_name pics.abc.com;
location / {
root /var/www/html;
index index.html index.htm index.php;
error_page 500 502 503 504 /50x.html;
location = /50x.html {
root html;
}
location ~ \_(\d+)x(\d+)\.(jpg|png|gif|jpeg|bmp)$ { //判断是否定制图
try_files $uri /temp/$uri /get.php; //判断是否已生成过定制图否则转交给/get.php
expires 30d;
}
location ~ \.php$ {
fastcgi_pass 127.0.0.1:9000;
fastcgi_index index.php;
fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
include fastcgi_params;
}
location ~ .*\.(gif|jpg|jpeg|png|bmp)$
{
expires 30d;
}
}
}
在/var/www/html我们以只读方式挂载Windows的目录，修改/etc/fstab,添加
\\192.168.2.3\f$\pics.abc.com\pics /var/www/html/pics/ cifs ro,username=user,password=pass 1 2
然后重启netfs服务，另外执行下面命令，安装依赖的包
yum -y install samba-client cifs-utils service netfs restart chkconfig netfs on
生成的缩率图会放到网站目录的temp目录下，如请求的http://pics.abc.com/pics/201604/29/abc_200x300.jpg
则生成的图片放在temp/pics/201604/29/abc_200x300.jpg目录下
PHP脚本:
function thumb($src, $width, $height, $filename, $mode = ‘scale‘, $quality = ‘100‘) {
try {
$imageValue = getimagesize($src);
$sourceWidth = $imageValue[0]; //原图宽
$sourceHeight = $imageValue[1]; //原图高
$thumbWidth = $width; //缩略图宽
$thumbHeight = $height; //缩略图高
$_x = 0;
$_y = 0;
$w = $sourceWidth;
$h = $sourceHeight;
if ($mode == ‘scale‘) {
if ($sourceWidth <= $thumbWidth && $sourceHeight <= $thumbHeight) {
$_x = floor(($thumbWidth - $sourceWidth) / 2);
$_y = floor(($thumbHeight - $sourceHeight) / 2);
$thumbWidth = $sourceWidth;
$thumbHeight = $sourceHeight;
} else {
if ($thumbHeight * $sourceWidth > $thumbWidth * $sourceHeight) {
$thumbHeight = floor($sourceHeight * $width / $sourceWidth);
$_y = floor(($height - $thumbHeight) / 2);
} else {
$thumbWidth = floor($sourceWidth * $height / $sourceHeight);
$_x = floor(($width - $thumbWidth) / 2);
}
}
} else if ($mode == ‘crop‘) {
if ($sourceHeight < $thumbHeight) { //如果原图尺寸小于当前尺寸
$thumbWidth = floor($thumbWidth * $sourceHeight / $thumbHeight);
$thumbHeight = $sourceHeight;
}
if ($sourceWidth < $thumbWidth) {
$thumbHeight = floor($thumbHeight * $sourceWidth / $thumbWidth);
$thumbWidth = $sourceWidth;
}
$s1 = $sourceWidth / $sourceHeight; //原图比例
$s2 = $width / $height; //新图比例
if ($s1 == $s2) {
} else if ($s1 > $s2) { //全高度
$y = 0;
$ax = floor($sourceWidth * ($thumbHeight / $sourceHeight));
$x = ($ax - $thumbWidth) / 2;
$w = $thumbWidth / ($thumbHeight / $sourceHeight);
} else { //全宽度
$x = 0;
$ay = floor($sourceHeight * ($thumbWidth / $sourceWidth)); //模拟原图比例高度
$y = ($ay - $thumbHeight) / 2;
$h = $thumbHeight / ($thumbWidth / $sourceWidth);
}
}
switch ($imageValue[2]) {
case 2: $source = imagecreatefromjpeg($src);
break;
case 1: $source = imagecreatefromgif($src);
break;
case 3: $source = imagecreatefrompng($src);
break;
case 6: $source = imagecreatefromwbmp($src);
break;
default: defulat();
return;
}
header("Content-type: image/jpeg");
$thumb = imagecreatetruecolor($width, $height);
imagefill($thumb, 0, 0, imagecolorallocate($thumb, 255, 255, 255));
imagecopyresampled($thumb, $source, 0, 0, $x, $y, $width, $height, $w, $h);
imagejpeg($thumb, null, $quality);
imagejpeg($thumb, $filename, $quality);
imagedestroy($thumb);
imagedestroy($source);
} catch (Exception $ex) {
defulat();
}
}
function defulat() {
/*
$default_img = realpath(‘../pictures/nopic.gif‘);
ob_start();
header(‘Content-type:image/jpeg‘);
readfile($default_img);
ob_flush();
flush();
*/
echo ‘error‘;
}
function mkDirs($dir){
if(!is_dir($dir)){
if(!mkDirs(dirname($dir))){
return false;
}
if(!mkdir($dir,0755)){
return false;
}
}
return true;
}
$uri=$_SERVER[‘REQUEST_URI‘];
$image=basename($uri);
$temp=‘./temp/‘.dirname($uri).‘/‘;
$imgpath=‘.‘.dirname($uri).‘/‘;
/*
//检查本地是否存在文件，原图
if(file_exists($temp.$image)){
ob_start();
header(‘Content-type:image/jpeg‘);
readfile($temp.$image);
ob_flush();
flush();
exit();
}
*/
//检查生成的图片是否曾经生成过，存在即返回，否则重新生成新图
if(!preg_match(‘/_(\d+)x(\d+)/‘, $image, $wh)){
ob_start();
header(‘Content-type:image/jpeg‘);
readfile($imgpath.$image);
ob_flush();
flush();
exit();
}
$width = $wh[1];
$height = $wh[2];
$source_img=preg_replace(‘/_(\d+)x(\d+)/‘, ‘‘, $image);
//对长宽都超过的图片返回原图
if($width>=2000 || $height>=2000){
ob_start();
header(‘Content-type:image/jpeg‘);
readfile($imgpath.$source_img);
ob_flush();
flush();
exit();
}
//图片处理
$src=$imgpath.$source_img;
$filename=$temp.$image;
mkDirs($temp);
//thumb(realpath($src), $width, $height, $filename, ‘crop‘, ‘85‘);
thumb(realpath($src), $width, $height, $filename, ‘crop‘, ‘100‘);
PHP生成尺寸部分参考<PHP图片自动裁切应付不同尺寸的显示>
淘宝通过URL生成不同尺寸的图片，思路
使用URLRewrite+实时处理+缓存
淘宝的图片就是使用这种方法来处理的。根据原图使用graphmagick去生成缩略图
简要得代码
nginx rewrite:
rewrite ^/upload/(.+)_(\d+)_(\d+)\.(jpg|png|gif) /upload/thumb.php?src=$1&w=$2&h=$3&type=$4;
php：
$src= $_REQUEST["src"];
$width = $_REQUEST["w"];
$height = $_REQUEST["h"];
$type = strtolower($_REQUEST["type"]);
$filename = $src.".".$width."x".$height.".".$type;
if(!file_exists($filename))
{
$im = new Imagick();
$im- > readImage($src);
if($im- > getImageWidth() > =$im- > getImageHeight())
{
$im- > cropThumbnailImage( $width, $height );
}else
{
$im- > cropImage($im- > getImageWidth(),$im- > getImageWidth(),0,0);
$im- > cropThumbnailImage($width,$height);
}
$im- > writeImage($filename);
$im- > destroy();
}
switch($type)
{
case "jpg":$contenttype = "jpeg";break;
case "jpeg":$contenttype = "jpeg";break;
case "png":$contenttype = "png";break;
case "gif":$contenttype = "gif";break;
}
header("Content-type:image/".$contenttype);
readfile($filename);
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