浅谈php扩展imagick

PHP建图通常都用GD库,因为是内置的不需要在服务器上额外安装插件,所以用起来比较省心,但是如果你的程序主要的功能就是处理图像,那麼就不建议用GD了,因为GD不但低效能而且能力也比较弱,佔用的系统资源也颇多,另外GD的creatfrom也有bug,而imagick却是一个很好的替代品,为此最近把我的一个项目由GD改成了imagick,但是改完之后出现了一些状况在此分享给大家.

首先说一下我这边出现的状况:

状况一:需要重写图像操作class

状况二:imagick多线程时会导致cpu使用率暴增到100%

在此顺便提一下imagick在centos6.4的安装方法:

1、安装ImageMagick

代码如下:

wget http://soft.vpser.net/web/imagemagick/ImageMagick-6.7.1-2.tar.gz
tar zxvf ImageMagick-6.7.1-2.tar.gz
cd ImageMagick-6.7.1-2/
./configure --prefix=/usr/local/imagemagick --disable-openmp
make && make install
ldconfig

测试ImageMagick是否可以正常运行：

代码如下:

/usr/local/imagemagick/bin/convert -version

2、安装PHP扩展：imagick

代码如下:

wget http://pecl.PHP.net/get/imagick-3.0.1.tgz
tar zxvf imagick-3.0.1.tgz
cd imagick-3.0.1/
/usr/local/PHP/bin/PHPize
./configure --with-PHP-config=/usr/local/PHP/bin/PHP-config --with-imagick=/usr/local/imagemagick
make && make install
ldconfig
vi /usr/local/PHP/etc/PHP.ini
添加：extension = "imagick.so"

重启lnmp

代码如下:

/root/lnmp reload

接下来我们针对上述两个状况分别提出解决办法:

状况一的解决办法如下:

代码如下:

/**
Imagick图像处理类
用法:
//引入Imagick物件
if(!defined('CLASS_IMAGICK')){require(Inc.'class_imagick.PHP');}
$Imagick=new class_imagick();
$Imagick->open('a.gif');
$Imagick->resize_to(100,100,'scale_fill');
$Imagick->add_text('1024i.com',10,20);
$Imagick->add_watermark('1024i.gif',50);
$Imagick->save_to('x.gif');
unset($Imagick);
/**/
define('CLASS_IMAGICK',TRUE);
class class_imagick{
private $image=null;
private $type=null;
// 构造
public function __construct(){}
// 析构
public function __destruct(){
if($this->image!==null){$this->image->destroy();}
}
// 载入图像
public function open($path){
if(!file_exists($path)){
$this->image=null;
return ;
}
$this->image=new Imagick($path);
if($this->image){
$this->type=strtolower($this->image->getImageFormat());
}
$this->image->stripImage();
return $this->image;
}
/**
图像裁切
/**/
public function crop($x=0,$y=0,$width=null,$height=null){
if($width==null) $width=$this->image->getImageWidth()-$x;
if($height==null) $height=$this->image->getImageHeight()-$y;
if($width<=0 || $height<=0) return;
if($this->type=='gif'){
$image=$this->image;
$canvas=new Imagick();
$images=$image->coalesceImages();
foreach($images as $frame){
$img=new Imagick();
$img->readImageBlob($frame);
$img->cropImage($width,$height,$x,$y);
$canvas->addImage($img);
$canvas->setImageDelay($img->getImageDelay());
$canvas->setImagePage($width,0);
}
$image->destroy();
$this->image=$canvas;
}else{
$this->image->cropImage($width,$y);
}
}
/**
更改图像大小
参数:
$width:新的宽度
$height:新的高度
$fit: 适应大小
'force': 把图像强制改为$width X $height
'scale': 按比例在$width X $height内缩放图片,结果不完全等於$width X $height
'scale_fill':按比例在$width X $height内缩放图片,没有像素的地方填充顏色$fill_color=array(255,255,255)(红,绿,蓝,透明度[0不透明-127全透明])
其他:智能模式,缩放图片并从正中裁切$width X $height的大小
注意:
$fit='force','scale','scale_fill'时输出完整图像
$fit=图像方位时输出指定位置部份的图像
字母与图像的对应关系如下:
north_west north north_east
west center east
south_west south south_east
/**/
public function resize_to($width=100,$height=100,$fit='center',$fill_color=array(255,0)){
switch($fit){
case 'force':
if($this->type=='gif'){
$image=$this->image;
$canvas=new Imagick();
$images=$image->coalesceImages();
foreach($images as $frame){
$img=new Imagick();
$img->readImageBlob($frame);
$img->thumbnailImage($width,false);
$canvas->addImage($img);
$canvas->setImageDelay($img->getImageDelay());
}
$image->destroy();
$this->image=$canvas;
}else{
$this->image->thumbnailImage($width,false);
}
break;
case 'scale':
if($this->type=='gif'){
$image=$this->image;
$images=$image->coalesceImages();
$canvas=new Imagick();
foreach($images as $frame){
$img=new Imagick();
$img->readImageBlob($frame);
$img->thumbnailImage($width,true);
$canvas->addImage($img);
$canvas->setImageDelay($img->getImageDelay());
}
$image->destroy();
$this->image=$canvas;
}else{
$this->image->thumbnailImage($width,true);
}
break;
case 'scale_fill':
$size=$this->image->getImagePage();
$src_width=$size['width'];
$src_height=$size['height'];
$x=0;
$y=0;
$dst_width=$width;
$dst_height=$height;
if($src_width*$height > $src_height*$width){
$dst_height=intval($width*$src_height/$src_width);
$y=intval(($height-$dst_height)/2);
}else{
$dst_width=intval($height*$src_width/$src_height);
$x=intval(($width-$dst_width)/2);
}
$image=$this->image;
$canvas=new Imagick();
$color='rgba('.$fill_color[0].','.$fill_color[1].','.$fill_color[2].','.$fill_color[3].')';
if($this->type=='gif'){
$images=$image->coalesceImages();
foreach($images as $frame){
$frame->thumbnailImage($width,true);
$draw=new ImagickDraw();
$draw->composite($frame->getImageCompose(),$y,$dst_width,$dst_height,$frame);
$img=new Imagick();
$img->newImage($width,$color,'gif');
$img->drawImage($draw);
$canvas->addImage($img);
$canvas->setImageDelay($img->getImageDelay());
$canvas->setImagePage($width,0);
}
}else{
$image->thumbnailImage($width,true);
$draw=new ImagickDraw();
$draw->composite($image->getImageCompose(),$image);
$canvas->newImage($width,$this->get_type());
$canvas->drawImage($draw);
$canvas->setImagePage($width,0);
}
$image->destroy();
$this->image=$canvas;
break;
default:
$size=$this->image->getImagePage();
$src_width=$size['width'];
$src_height=$size['height'];
$crop_x=0;
$crop_y=0;
$crop_w=$src_width;
$crop_h=$src_height;
if($src_width*$height > $src_height*$width){
$crop_w=intval($src_height*$width/$height);
}else{
$crop_h=intval($src_width*$height/$width);
}
switch($fit){
case 'north_west':
$crop_x=0;
$crop_y=0;
break;
case 'north':
$crop_x=intval(($src_width-$crop_w)/2);
$crop_y=0;
break;
case 'north_east':
$crop_x=$src_width-$crop_w;
$crop_y=0;
break;
case 'west':
$crop_x=0;
$crop_y=intval(($src_height-$crop_h)/2);
break;
case 'center':
$crop_x=intval(($src_width-$crop_w)/2);
$crop_y=intval(($src_height-$crop_h)/2);
break;
case 'east':
$crop_x=$src_width-$crop_w;
$crop_y=intval(($src_height-$crop_h)/2);
break;
case 'south_west':
$crop_x=0;
$crop_y=$src_height-$crop_h;
break;
case 'south':
$crop_x=intval(($src_width-$crop_w)/2);
$crop_y=$src_height-$crop_h;
break;
case 'south_east':
$crop_x=$src_width-$crop_w;
$crop_y=$src_height-$crop_h;
break;
default:
$crop_x=intval(($src_width-$crop_w)/2);
$crop_y=intval(($src_height-$crop_h)/2);
}
$image=$this->image;
$canvas=new Imagick();
if($this->type=='gif'){
$images=$image->coalesceImages();
foreach($images as $frame){
$img=new Imagick();
$img->readImageBlob($frame);
$img->cropImage($crop_w,$crop_h,$crop_x,$crop_y);
$img->thumbnailImage($width,true);
$canvas->addImage($img);
$canvas->setImageDelay($img->getImageDelay());
$canvas->setImagePage($width,0);
}
}else{
$image->cropImage($crop_w,$crop_y);
$image->thumbnailImage($width,true);
$canvas->addImage($image);
$canvas->setImagePage($width,0);
}
$image->destroy();
$this->image=$canvas;
}
}
/**
添加图片水印
参数:
$path:水印图片(包含完整路径)
$x,$y:水印座标
/**/
public function add_watermark($path,$x=0,$y=0){
$watermark=new Imagick($path);
$draw=new ImagickDraw();
$draw->composite($watermark->getImageCompose(),$watermark->getImageWidth(),$watermark->getimageheight(),$watermark);
if($this->type=='gif'){
$image=$this->image;
$canvas=new Imagick();
$images=$image->coalesceImages();
foreach($image as $frame){
$img=new Imagick();
$img->readImageBlob($frame);
$img->drawImage($draw);
$canvas->addImage($img);
$canvas->setImageDelay($img->getImageDelay());
}
$image->destroy();
$this->image=$canvas;
}else{
$this->image->drawImage($draw);
}
}
/**
添加文字水印
参数:
$text:水印文字
$x,$y:水印座标
/**/
public function add_text($text,$angle=0,$style=array()){
$draw=new ImagickDraw();
if(isset($style['font'])) $draw->setFont($style['font']);
if(isset($style['font_size'])) $draw->setFontSize($style['font_size']);
if(isset($style['fill_color'])) $draw->setFillColor($style['fill_color']);
if(isset($style['under_color'])) $draw->setTextUnderColor($style['under_color']);
if($this->type=='gif'){
foreach($this->image as $frame){
$frame->annotateImage($draw,$angle,$text);
}
}else{
$this->image->annotateImage($draw,$text);
}
}
/**
图片存档
参数:
$path:存档的位置和新的档案名
/**/
public function save_to($path){
$this->image->stripImage();
switch($this->type){
case 'gif':
$this->image->writeImages($path,true);
return ;
case 'jpg':
case 'jpeg':
$this->image->setImageCompressionQuality($_ENV['ImgQ']);
$this->image->writeImage($path);
return ;
case 'png':
$flag = $this->image->getImageAlphaChannel();
// 如果png背景不透明则压缩
if(imagick::ALPHACHANNEL_UNDEFINED == $flag or imagick::ALPHACHANNEL_DEACTIVATE == $flag){
$this->image->setImageType(imagick::IMGTYPE_PALETTE);
$this->image->writeImage($path);
}else{
$this->image->writeImage($path);
}unset($flag);
return ;
default:
$this->image->writeImage($path);
return ;
}
}
// 直接输出图像到萤幕
public function output($header=true){
if($header) header('Content-type: '.$this->type);
echo $this->image->getImagesBlob();
}
/**
建立缩小图
$fit为真时,将保持比例并在$width X $height内產生缩小图
/**/
public function thumbnail($width=100,$fit=true){$this->image->thumbnailImage($width,$fit);}
/**
给图像添加边框
$width: 左右边框宽度
$height: 上下边框宽度
$color: 顏色
/**/
public function border($width,$color='rgb(220,220,220)'){
$color=new ImagickPixel();
$color->setColor($color);
$this->image->borderImage($color,$width,$height);
}
//取得图像宽度
public function get_width(){$size=$this->image->getImagePage();return $size['width'];}
//取得图像高度
public function get_height(){$size=$this->image->getImagePage();return $size['height'];}
// 设置图像类型
public function set_type($type='png'){$this->type=$type;$this->image->setImageFormat($type);}
// 取得图像类型
public function get_type(){return $this->type;}
public function blur($radius,$sigma){$this->image->blurImage($radius,$sigma);} // 模糊
public function gaussian_blur($radius,$sigma){$this->image->gaussianBlurImage($radius,$sigma);} // 高斯模糊
public function motion_blur($radius,$sigma,$angle){$this->image->motionBlurImage($radius,$angle);} // 运动模糊
public function radial_blur($radius){$this->image->radialBlurImage($radius);} // 径向模糊
public function add_noise($type=null){$this->image->addNoiseImage($type==null?imagick::NOISE_IMPULSE:$type);} // 添加噪点
public function level($black_point,$gamma,$white_point){$this->image->levelImage($black_point,$white_point);} // 调整色阶
public function modulate($brightness,$saturation,$hue){$this->image->modulateImage($brightness,$hue);} // 调整亮度,饱和度,色调
public function charcoal($radius,$sigma){$this->image->charcoalImage($radius,$sigma);} // 素描效果
public function oil_paint($radius){$this->image->oilPaintImage($radius);} // 油画效果
public function flop(){$this->image->flopImage();} // 水平翻转
public function flip(){$this->image->flipImage();} // 垂直翻转
}

状况二的解决办法如下:

首先用/usr/local/imagemagick/bin/convert -version指令查看一下输出内容是否已经开啟了多线程,Features:的值为空说明是单线程,如果Features:的值是openMP说明是多线程.imagick的多线程模式有一个bug,他会导致多核心的cpu使用率瞬间飆升到100所以一定要使用它的单线程模式才行.

代码如下:

Version: ImageMagick 6.7.1-2 2014-05-29 Q16 http://www.imagemagick.org
Copyright: Copyright (C) 1999-2011 ImageMagick Studio LLC
Features:

上边是我配置正确时显示的结果,如果没有配置正确会显示下边的结果

代码如下:

Version: ImageMagick 6.7.1-2 2014-05-29 Q16 http://www.imagemagick.org
Copyright: Copyright (C) 1999-2011 ImageMagick Studio LLC
Features: openMP

第一种结果是单线程模式,第二种结果是多线程模式,因为imagick的多线程模式有bug,所以如果您刚开始是用多线程模式安装的imagick那就必须要yum remove imagemagick将其卸载掉重新安装才行.

经过重写class,重装imagick之后一切正常,而且处理图像的效能比之以前有了大幅提升

浅谈php扩展imagick

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