php 缩略图生成类(支持imagemagick与gd库)

<?php 
/** 缩略图生成类,支持imagemagick及gd库两种处理
*   Date:   2013-07-15
*   Author: fdipzone
*   Ver:    1.2
*   edit: www.jb200.com
*   Func:
*   public  set_config: 设置参数
*   public  create_thumb: 生成缩略图
*   private fit: 缩略图片
*   private crop: 裁剪图片
*   private gd_fit: GD库缩略图片
*   private gd_crop: GD库裁剪图片
*   private get_size: 获取要转换的size
*   private get_crop_offset: 获取裁图的偏移量
*   private add_watermark: 添加水印
*   private check_handler: 判断处理程序是否已安装
*   private create_dirs: 创建目录
*   private exists: 判断参数是否存在
*   private to_log: 记录log
*   private hex2rgb: hex颜色转rgb颜色
*   private get_file_ext: 获取图片类型
*
*   ver:    1.1 增加GD库处理
*   ver:    1.2 增加width,height错误参数处理
*               增加当图片colorspace不为RGB时作转RGB处理
*               修正使用crop保存为gif时出现透明无效区域问题，使用+repage参数，删除透明无效区域即可
*
*   tips:建议使用imagemagick
*        GD库不支持透明度水印,如果必须使用透明水印,请将水印图片做成有透明度。
*        GD库输出gif如加透明水印，会有问题。
*/ 
 
class PicThumb{ // class start 
 
    private $_log = null;            // log file 
    private $_handler = null;        // 进行图片处理的程序,imagemagick/gd库 
    private $_type = 'fit';          // fit or crop 
    private $_source = null;         // 原图路径 
    private $_dest = null;           // 缩略图路径 
    private $_watermark = null;      // 水印图片 
    private $_opacity = 75;          // 水印圖片透明度,gd库不支持 
    private $_gravity = 'SouthEast'; // 水印摆放位置 NorthWest, North, NorthEast, West, Center, East, SouthWest, South, SouthEast 
    private $_geometry = '+10+10';   // 水印定位,gd库不支持 
    private $_croppos = 'TL';        // 截图的位置 TL TM TR ML MM MR BL BM BR 
    private $_bgcolor = null;        // 填充的背景色 
    private $_quality = 90;          // 生成的图片质量 
    private $_width = null;          // 指定区域宽度 
    private $_height = null;         // 指定区域高度 
 
 
    // 初始化 
    public function __construct($logfile=''){ 
        if($logfile!=''){ 
            $this->_log = $logfile; 
        } 
    } 
 
 
    // 设置参数 
    public function set_config($param=array()){ 
        $this->_handler = $this->exists($param, 'handler')? strtolower($param['handler']) : null; 
        $this->_type = $this->exists($param, 'type')? strtolower($param['type']) : 'fit'; 
        $this->_watermark = $this->exists($param, 'watermark')? $param['watermark'] : null; 
        $this->_opacity = $this->exists($param, 'opacity')? $param['opacity'] : 75; 
        $this->_gravity = $this->exists($param, 'gravity')? $param['gravity'] : 'SouthEast'; 
        $this->_geometry = $this->exists($param, 'geometry')? $param['geometry'] : '+10+10'; 
        $this->_croppos = $this->exists($param, 'croppos')? $param['croppos'] : 'TL'; 
        $this->_bgcolor = $this->exists($param, 'bgcolor')? $param['bgcolor'] : null; 
        $this->_quality = $this->exists($param, 'quality')? $param['quality'] : 90; 
        $this->_width = $this->exists($param, 'width')? $param['width'] : null; 
        $this->_height = $this->exists($param, 'height')? $param['height'] : null; 
    }
 
    /** 创建缩略图
    * @param String $source 原图
    * @param String $dest   目标图
    * @return boolean
    */ 
    public function create_thumb($source, $dest){ 
 
        // 检查使用的handler是否已安装 
        if(!$this->check_handler()){ 
            $this->to_log('handler not installed'); 
            return false; 
        } 
 
        // 判断区域宽高是否正确 
        if(!is_numeric($this->_width) || !is_numeric($this->_height) || $this->_width<=0 || $this->_height<=0){ 
            $this->to_log('width or height invalid'); 
            return false; 
        } 
 
        // 判断源文件是否存在 
        if(!file_exists($source)){ 
            $this->to_log($source.' not exists'); 
            return false; 
        } 
 
        // 创建目标文件路径 
        if(!$this->create_dirs($dest)){ 
            $this->to_log(dirname($dest).' create fail'); 
            return false; 
        } 
 
        $this->_source = $source;   // 源文件 
        $this->_dest = $dest;       // 目标文件 
 
        // 处理图片 
        switch($this->_type){ 
            case 'fit': 
                if($this->_handler=='imagemagick'){ 
                    return $this->fit(); 
                }else{ 
                    return $this->gd_fit(); 
                } 
                break; 
 
            case 'crop': 
                if($this->_handler=='imagemagick'){ 
                    return $this->crop(); 
                }else{ 
                    return $this->gd_crop(); 
                } 
                break; 
 
            default: 
                $this->to_log($this->_type.' not fit and crop'); 
                return false; 
        } 
 
    } 
 
 
    /** 按比例压缩或拉伸图片
    * @return boolean
    */ 
    private function fit(){ 
 
        // 判断是否填充背景 
        $bgcolor = ($this->_bgcolor!=null)?  
        sprintf(" -background '%s' -gravity center -extent '%sx%s' ", $this->_bgcolor, $this->_width, $this->_height) : ""; 
 
        // 判断是否要转为RGB 
        $source_info = getimagesize($this->_source); 
        $colorspace = (!isset($source_info['channels']) || $source_info['channels']!=3)? ' -colorspace RGB ' : ''; 
 
        // 命令行 
        $cmd = sprintf("convert -resize '%sx%s' '%s' %s -quality %s %s '%s'", $this->_width, $this->_height, $this->_source, $bgcolor, $this->_quality, $colorspace, $this->_dest); 
 
        // 记录执行的命令 
        $this->to_log($cmd); 
 
        // 执行命令 
        exec($cmd); 
 
        // 添加水印 
        $this->add_watermark($this->_dest); 
 
        return is_file($this->_dest)? true : false; 
 
    } 
 
 
    /** 裁剪图片
    * @return boolean
    */ 
    private function crop(){ 
 
        // 获取生成的图片尺寸 
        list($pic_w, $pic_h) = $this->get_size(); 
 
        // 获取截图的偏移量 
        list($offset_w, $offset_h) = $this->get_crop_offset($pic_w, $pic_h); 
 
        // 判断是否要转为RGB 
        $source_info = getimagesize($this->_source); 
        $colorspace = (!isset($source_info['channels']) || $source_info['channels']!=3)? ' -colorspace RGB ' : ''; 
 
        // 命令行 
        $cmd = sprintf("convert -resize '%sx%s' '%s' -quality %s %s -crop %sx%s+%s+%s +repage '%s'", $pic_w, $pic_h, $this->_source, $this->_quality, $colorspace, $this->_width, $this->_height, $offset_w, $offset_h, $this->_dest); 
 
        // 记录执行的命令 
        $this->to_log($cmd); 
 
        // 执行命令 
        exec($cmd); 
 
        // 添加水印 
        $this->add_watermark($this->_dest); 
 
        return is_file($this->_dest)? true : false; 
 
    } 
 
 
    /** GD库按比例压缩或拉伸图片
    * @return boolean
    */ 
    private function gd_fit(){ 
 
        // 获取生成的图片尺寸 
        list($pic_w, $pic_h) = $this->get_size(); 
 
        list($owidth, $oheight, $otype) = getimagesize($this->_source); 
 
        switch($otype){ 
            case 1: $source_img = imagecreatefromgif($this->_source); break; 
            case 2: $source_img = imagecreatefromjpeg($this->_source); break; 
            case 3: $source_img = imagecreatefrompng($this->_source); break; 
            default: return false; 
        } 
 
        // 按比例缩略/拉伸图片 
        $new_img = imagecreatetruecolor($pic_w, $pic_h); 
        imagecopyresampled($new_img, $source_img, 0, 0, 0, 0, $pic_w, $pic_h, $owidth, $oheight); 
 
        // 判断是否填充背景 
        if($this->_bgcolor!=null){ 
            $bg_img = imagecreatetruecolor($this->_width, $this->_height); 
            $rgb = $this->hex2rgb($this->_bgcolor); 
            $bgcolor =imagecolorallocate($bg_img, $rgb['r'], $rgb['g'], $rgb['b']); 
            imagefill($bg_img, 0, 0, $bgcolor); 
            imagecopy($bg_img, $new_img, (int)(($this->_width-$pic_w)/2), (int)(($this->_height-$pic_h)/2), 0, 0, $pic_w, $pic_h); 
            $new_img = $bg_img; 
        } 
 
        // 获取目标图片的类型 
        $dest_ext = $this->get_file_ext($this->_dest); 
 
        // 生成图片 
        switch($dest_ext){ 
            case 1: imagegif($new_img, $this->_dest, $this->_quality); break; 
            case 2: imagejpeg($new_img, $this->_dest, $this->_quality); break; 
            case 3: imagepng($new_img, $this->_dest, (int)(($this->_quality-1)/10)); break; 
        } 
 
        if(isset($source_img)){ 
            imagedestroy($source_img); 
        } 
 
        if(isset($new_img)){ 
            imagedestroy($new_img); 
        } 
 
        // 添加水印 
        $this->add_watermark($this->_dest); 
 
        return is_file($this->_dest)? true : false; 
 
    } 
 
 
    /** GD库裁剪图片
    * @return boolean
    */ 
    private function gd_crop(){ 
 
        // 获取生成的图片尺寸 
        list($pic_w, $pic_h) = $this->get_size(); 
 
        // 获取截图的偏移量 
        list($offset_w, $offset_h) = $this->get_crop_offset($pic_w, $pic_h); 
 
        list($owidth, $oheight, $otype) = getimagesize($this->_source); 
 
        switch($otype){ 
            case 1: $source_img = imagecreatefromgif($this->_source); break; 
            case 2: $source_img = imagecreatefromjpeg($this->_source); break; 
            case 3: $source_img = imagecreatefrompng($this->_source); break; 
            default: return false; 
        } 
 
        // 按比例缩略/拉伸图片 
        $tmp_img = imagecreatetruecolor($pic_w, $pic_h); 
        imagecopyresampled($tmp_img, $source_img, 0, 0, 0, 0, $pic_w, $pic_h, $owidth, $oheight); 
 
        // 裁剪图片 
        $new_img = imagecreatetruecolor($this->_width, $this->_height); 
        imagecopyresampled($new_img, $tmp_img, 0, 0, $offset_w, $offset_h, $this->_width, $this->_height, $this->_width, $this->_height); 
 
        // 获取目标图片的类型 
        $dest_ext = $this->get_file_ext($this->_dest); 
 
        // 生成图片 
        switch($dest_ext){ 
            case 1: imagegif($new_img, $this->_dest, $this->_quality); break; 
            case 2: imagejpeg($new_img, $this->_dest, $this->_quality); break; 
            case 3: imagepng($new_img, $this->_dest, (int)(($this->_quality-1)/10)); break; 
        } 
 
        if(isset($source_img)){ 
            imagedestroy($source_img); 
        } 
 
        if(isset($tmp_img)){ 
            imagedestroy($tmp_img); 
        } 
 
        if(isset($new_img)){ 
            imagedestroy($new_img); 
        } 
 
        // 添加水印 
        $this->add_watermark($this->_dest); 
 
        return is_file($this->_dest)? true : false; 
 
    } 
 
 
    /** 获取目标图生成的size
    * @return Array $width, $height
    */ 
    private function get_size(){ 
        list($owidth, $oheight) = getimagesize($this->_source); 
        $width = (int)($this->_width); 
        $height = (int)($this->_height); 
         
        switch($this->_type){ 
            case 'fit': 
                $pic_w = $width; 
                $pic_h = (int)($pic_w*$oheight/$owidth); 
                if($pic_h>$height){ 
                    $pic_h = $height; 
                    $pic_w = (int)($pic_h*$owidth/$oheight); 
                } 
                break; 
            case 'crop': 
                if($owidth>$oheight){ 
                    $pic_h = $height; 
                    $pic_w = (int)($pic_h*$owidth/$oheight); 
                }else{ 
                    $pic_w = $width; 
                    $pic_h = (int)($pic_w*$oheight/$owidth); 
                } 
                break; 
        } 
 
        return array($pic_w, $pic_h); 
    } 
 
 
    /** 获取截图的偏移量
    * @param int $pic_w 图宽度
    * @param int $pic_h 图高度
    * @return Array $offset_w, $offset_h
    */ 
    private function get_crop_offset($pic_w, $pic_h){ 
        $offset_w = 0; 
        $offset_h = 0; 
         
        switch(strtoupper($this->_croppos)){ 
            case 'TL': 
                $offset_w = 0; 
                $offset_h = 0; 
                break; 
 
            case 'TM': 
                $offset_w = (int)(($pic_w-$this->_width)/2); 
                $offset_h = 0; 
                break; 
 
            case 'TR': 
                $offset_w = (int)($pic_w-$this->_width); 
                $offset_h = 0; 
                break; 
 
            case 'ML': 
                $offset_w = 0; 
                $offset_h = (int)(($pic_h-$this->_height)/2); 
                break; 
 
            case 'MM': 
                $offset_w = (int)(($pic_w-$this->_width)/2); 
                $offset_h = (int)(($pic_h-$this->_height)/2); 
                break; 
 
            case 'MR': 
                $offset_w = (int)($pic_w-$this->_width); 
                $offset_h = (int)(($pic_h-$this->_height)/2); 
                break; 
 
            case 'BL': 
                $offset_w = 0; 
                $offset_h = (int)($pic_h-$this->_height); 
                break; 
 
            case 'BM': 
                $offset_w = (int)(($pic_w-$this->_width)/2); 
                $offset_h = (int)($pic_h-$this->_height); 
                break; 
 
            case 'BR': 
                $offset_w = (int)($pic_w-$this->_width); 
                $offset_h = (int)($pic_h-$this->_height); 
                break; 
        } 
 
        return array($offset_w, $offset_h); 
    } 
 
 
    /** 添加水印
    * @param String $dest 图片路径
    */ 
    private function add_watermark($dest){ 
        if($this->_watermark!=null && file_exists($this->_watermark) && file_exists($dest)){ 
            list($owidth, $oheight, $otype) = getimagesize($dest); 
            list($w, $h, $wtype) = getimagesize($this->_watermark); 
 
            // 水印图比原图要小才加水印 
            if($w<=$owidth && $h<=$oheight){ 
 
                if($this->_handler=='imagemagick'){ // imagemagick 添加水印 
 
                    $cmd = sprintf("composite -gravity %s -geometry %s -dissolve %s '%s' %s %s", $this->_gravity, $this->_geometry, $this->_opacity, $this->_watermark, $dest, $dest); 
 
                    $this->to_log($cmd); 
 
                    exec($cmd); 
 
                }else{ // gd 添加水印 
 
                    switch($wtype){ 
                        case 1: $water_img = imagecreatefromgif($this->_watermark); break; 
                        case 2: $water_img = imagecreatefromjpeg($this->_watermark); break; 
                        case 3: $water_img = imagecreatefrompng($this->_watermark); break; 
                        default: return false; 
                    } 
 
                    switch($otype){ 
                        case 1: $dest_img = imagecreatefromgif($dest); break; 
                        case 2: $dest_img = imagecreatefromjpeg($dest); break; 
                        case 3: $dest_img = imagecreatefrompng($dest); break; 
                        default: return false; 
                    } 
 
                    // 水印位置 
                    switch(strtolower($this->_gravity)){ 
                        case 'northwest': 
                            $posX = 0; 
                            $posY = 0; 
                            break; 
                        case 'north': 
                            $posX = ($owidth - $w) / 2; 
                            $posY = 0; 
                            break; 
                        case 'northeast': 
                            $posX = $owidth - $w; 
                            $posY = 0; 
                            break; 
                        case 'west': 
                            $posX = 0; 
                            $posY = ($oheight - $h) / 2; 
                            break; 
                        case 'center': 
                            $posX = ($owidth - $w) / 2; 
                            $posY = ($oheight - $h) / 2; 
                            break; 
                        case 'east': 
                            $posX = $owidth - $w; 
                            $posY = ($oheight - $h) / 2; 
                            break; 
                        case 'southwest': 
                            $posX = 0; 
                            $posY = $oheight - $h; 
                            break; 
                        case 'south': 
                            $posX = ($owidth - $w) / 2; 
                            $posY = $oheight - $h; 
                            break; 
                        case 'southeast': 
                            $posX = $owidth - $w; 
                            $posY = $oheight - $h; 
                            break; 
                    } 
 
                    imagealphablending($dest_img, true); 
                    imagecopy($dest_img, $water_img, $posX, $posY, 0, 0, $w, $h); 
 
                    switch($otype){ 
                        case 1:imagegif($dest_img, $dest, $this->_quality); break; 
                        case 2:imagejpeg($dest_img, $dest, $this->_quality); break; 
                        case 3:imagepng($dest_img, $dest, (int)(($this->_quality-1)/10)); break; 
                    } 
 
                    if(isset($water_img)){ 
                        imagedestroy($water_img); 
                    } 
 
                    if(isset($dest_img)){ 
                        imagedestroy($dest_img); 
                    } 
 
                } 
            } 
        } 
    } 
 
 
    /** 判断处理程序是否已安装
    * @return boolean
    */ 
    private function check_handler(){ 
 
        $handler = $this->_handler; 
 
        if(!in_array($handler, array('imagemagick', 'gd', null))){ 
            return false; 
        } 
 
        // 检查是否有安装imagemagick 
        $imagemagick_installed = strstr(shell_exec('convert -version'),'Version: ImageMagick')!=''? true : false; 
 
        // 检查是否有安装gd库 
        $gd_installed = function_exists('gd_info')? true : false; 
 
        switch($handler){ 
            case 'imagemagick': 
                return $imagemagick_installed; 
                break; 
 
            case 'gd': 
                return $gd_installed; 
                break; 
 
            case null: 
                if($imagemagick_installed){ 
                    $this->_handler = 'imagemagick'; 
                    return true; 
                } 
 
                if($gd_installed){ 
                    $this->_handler = 'gd'; 
                    return true; 
                } 
                break; 
        } 
 
        return false; 
    } 
 
 
    /** 创建图片目录
    * @param String $path
    * @return boolean
    */ 
    private function create_dirs($dest){ 
        if(!is_dir(dirname($dest))){ 
            return mkdir(dirname($dest), 0777, true); 
        } 
        return true; 
    } 
 
 
    /** 判断参数是否存在
    * @param  Array   $obj  数组对象
    * @param  String  $key  要查找的key
    * @return boolean
    */ 
    private function exists($obj,$key=''){ 
        if($key==''){ 
            return isset($obj) && !empty($obj); 
        }else{ 
            $keys = explode('.',$key); 
            for($i=0,$max=count($keys); $i<$max; $i++){ 
                if(isset($obj[$keys[$i]])){ 
                    $obj = $obj[$keys[$i]]; 
                }else{ 
                    return false; 
                } 
            } 
            return isset($obj) && !empty($obj); 
        } 
    } 
 
 
    /** 记录log
    * @param String $msg 要记录的log讯息
    */ 
    private function to_log($msg){ 
        if($this->_log){ 
            $msg = '['.date('Y-m-d H:i:s').']'.$msg."rn"; 
            file_put_contents($this->_log, $msg, FILE_APPEND); 
        } 
    } 
 
 
    /** hex颜色转rgb颜色
    * @param  String $color hex颜色
    * @return Array
    */ 
    private function hex2rgb($hexcolor){ 
        $color = str_replace('#', '', $hexcolor); 
        if (strlen($color) > 3) { 
            $rgb = array( 
                'r' => hexdec(substr($color, 0, 2)), 
                'g' => hexdec(substr($color, 2, 2)), 
                'b' => hexdec(substr($color, 4, 2)) 
            ); 
        } else { 
            $r = substr($color, 0, 1) . substr($color, 0, 1); 
            $g = substr($color, 1, 1) . substr($color, 1, 1); 
            $b = substr($color, 2, 1) . substr($color, 2, 1); 
            $rgb = array( 
                'r' => hexdec($r), 
                'g' => hexdec($g), 
                'b' => hexdec($b) 
            ); 
        } 
        return $rgb; 
    } 
 
 
    /** 获取图片类型
    * @param  String $file 图片路径
    * @return int
    */ 
    private function get_file_ext($file){ 
        $filename = basename($file); 
        list($name, $ext)= explode('.', $filename); 
 
        $ext_type = 0; 
 
        switch(strtolower($ext)){ 
            case 'jpg': 
            case 'jpeg': 
                $ext_type = 2; 
                break; 
            case 'gif': 
                $ext_type = 1; 
                break; 
            case 'png': 
                $ext_type = 3; 
                break; 
        } 
 
        return $ext_type; 
    } 
 
} // class end 
 
?> 
demo：
[php] view plaincopy
<?php 
define('ROOT', dirname(__FILE__)); 
 
require(ROOT."/PicThumb.class.php"); 
 
$logfile = ROOT.'/PicThumb.log'; 
$source1 = ROOT.'/pic/source.jpg'; 
$dest1 = ROOT.'/pic/1.jpg'; 
$dest2 = ROOT.'/pic/2.gif'; 
$dest3 = ROOT.'/pic/3.png'; 
 
$source2 = ROOT.'/pic/source_cmyk.jpg'; 
$dest4 = ROOT.'/pic/4.jpg'; 
$dest5 = ROOT.'/pic/5.gif'; 
$dest6 = ROOT.'/pic/6.png'; 
 
$watermark = ROOT.'/pic/watermark.png'; 
 
// 按比例生成缩略图 
$param = array( 
    'type' => 'fit', 
    'width' => 100, 
    'height' => 100, 
); 
 
$obj = new PicThumb($logfile); 
$obj->set_config($param); 
$flag = $obj->create_thumb($source1, $dest1); 
 
if($flag){  // www.jb200.com
    echo '<img src="pic/'.basename($dest1).'">'; 
}else{ 
    echo 'create thumb fail'; 
}
 
// 按比例生成缩略图,不足部分用#FF0000填充 
$param = array( 
    'type' => 'fit', 
    'width' => 100, 
    'height' => 100, 
    'bgcolor' => '#FFFF00' 
); 
 
$obj = new PicThumb($logfile); 
$obj->set_config($param); 
$flag = $obj->create_thumb($source1, $dest2); 
 
if($flag){ 
    echo '<img src="pic/'.basename($dest2).'">'; 
}else{ 
    echo 'create thumb fail'; 
} 
 
// 裁剪250x250的缩略图,裁剪位置是底部中间,水印位置西南,透明度50 
$param = array( 
    'type' => 'crop', 
    'croppos' => 'BM', 
    'width' => 250, 
    'height' => 250, 
    'watermark' => $watermark, 
    'opacity' => 50, 
    'gravity' => 'SouthWest' 
); 
 
$obj = new PicThumb($logfile); 
$obj->set_config($param); 
$flag = $obj->create_thumb($source1, $dest3); 
 
if($flag){ 
    echo '<img src="pic/'.basename($dest3).'">'; 
}else{ 
    echo 'create thumb fail'; 
} 
 
// 按比例生成缩略图 CMYK格式 
$param = array( 
    'type' => 'fit', 
    'width' => 100, 
    'height' => 100, 
); 
 
$obj = new PicThumb($logfile); 
$obj->set_config($param); 
$flag = $obj->create_thumb($source2, $dest4); 
 
if($flag){ 
    echo '<img src="pic/'.basename($dest4).'">'; 
}else{ 
    echo 'create thumb fail'; 
}

// 按比例生成缩略图,不足部分用#FF0000填充 CMYK格式 
$param = array( 
    'type' => 'fit', 
    'width' => 100, 
    'height' => 100, 
    'bgcolor' => '#FFFF00' 
); 
 
$obj = new PicThumb($logfile); 
$obj->set_config($param); 
$flag = $obj->create_thumb($source2, $dest5); 
 
if($flag){ 
    echo '<img src="pic/'.basename($dest5).'">'; 
}else{ 
    echo 'create thumb fail'; 
} 
 
// 裁剪250x250的缩略图,裁剪位置是底部中间,水印位置西南,透明度50 CMYK格式 
$param = array( 
    'type' => 'crop', 
    'croppos' => 'BM', 
    'width' => 250, 
    'height' => 250, 
    'watermark' => $watermark, 
    'opacity' => 50, 
    'gravity' => 'SouthWest' 
); 
 
$obj = new PicThumb($logfile); 
$obj->set_config($param); 
$flag = $obj->create_thumb($source2, $dest6); 
 
if($flag){ 
    echo '<img src="pic/'.basename($dest6).'">'; 
}else{ 
    echo 'create thumb fail'; 
} 
?>