php扩展imagick实例详解

imagick是一个可以供PHP调用ImageMagick功能的PHP扩展。使用这个扩展可以使PHP具备和ImageMagick相同的功能。

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.

需求:
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%

imagick在centos6.4的安装方法（php如何添加imagick扩展？）:
1、安装ImageMagick

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

2、安装PHP扩展：imagick

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
/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:
/**
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',10,50);

$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,$height,0,0);

}

$image->destroy();

$this->image=$canvas;

}else{

$this->image->cropImage($width,$height,$x,$y);

} www.jbxue.com

}

/**

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(255,255,255,0)){

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,$height,false);

$canvas->addImage($img);

$canvas->setImageDelay($img->getImageDelay());

}

$image->destroy();

$this->image=$canvas;

}else{

$this->image->thumbnailImage($width,$height,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,$height,true);

$canvas->addImage($img);

$canvas->setImageDelay($img->getImageDelay());

}

$image->destroy();

$this->image=$canvas;

}else{

$this->image->thumbnailImage($width,$height,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,$height,true);

$draw=new ImagickDraw();

$draw->composite($frame->getImageCompose(),$x,$y,$dst_width,$dst_height,$frame);

$img=new Imagick();

$img->newImage($width,$height,$color,'gif');

$img->drawImage($draw);

$canvas->addImage($img);

$canvas->setImageDelay($img->getImageDelay());

$canvas->setImagePage($width,$height,0,0);

}

}else{

$image->thumbnailImage($width,$height,true);

$draw=new ImagickDraw();

$draw->composite($image->getImageCompose(),$x,$y,$dst_width,$dst_height,$image);

$canvas->newImage($width,$height,$color,$this->get_type());

$canvas->drawImage($draw);

$canvas->setImagePage($width,$height,0,0);

}

$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,$height,true);

$canvas->addImage($img);

$canvas->setImageDelay($img->getImageDelay());

$canvas->setImagePage($width,$height,0,0);

} www.jbxue.com

}else{

$image->cropImage($crop_w,$crop_h,$crop_x,$crop_y);

$image->thumbnailImage($width,$height,true);

$canvas->addImage($image);

$canvas->setImagePage($width,$height,0,0);

}

$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(),$x,$y,$watermark->getImageWidth(),$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($text,$x=0,$y=0,$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,$x,$y,$angle,$text);

}

}else{

$this->image->annotateImage($draw,$x,$y,$angle,$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($width=100,$height=100,$fit=true){$this->image->thumbnailImage($width,$height,$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($width,$height,$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($radius,$sigma,$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($black_point,$gamma,$white_point);} // 调整色阶

public function modulate($brightness,$saturation,$hue){$this->image->modulateImage($brightness,$saturation,$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:

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