php实现的支持imagemagick及gd库两种处理的缩略图生成类

本文实例讲述了php实现的支持imagemagick及gd库两种处理的缩略图生成类及其用法实例，非常具有实用价值。分享给大家供大家参考。具体如下：

一、功能:

1.按比例缩小/放大 2.填充背景色 3.按区域裁剪 4.添加水印，包括水印的位置，透明度等

使用imagemagick/GD库实现，imagemagick地址：www.imagemagick.org 需要安装imagemagick，安装方法如下：

二、实现方法：

PicThumb.class.php类文件如下：

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->_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,$pic_h,$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,$source_img,$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,$bgcolor);
  imagecopy($bg_img,$new_img,(int)(($this->_width-$pic_w)/2),(int)(($this->_height-$pic_h)/2),$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->_quality); break;
  case 3: imagepng($new_img,(int)(($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);

  list($owidth,$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,$oheight);

  // 裁剪图片
  $new_img = imagecreatetruecolor($this->_width,$this->_height);
  imagecopyresampled($new_img,$tmp_img,$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,(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,$otype) = getimagesize($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,$posY,$w,$h); 
  
    switch($otype){ 
      case 1:imagegif($dest_img,$this->_quality); break; 
      case 2:imagejpeg($dest_img,$this->_quality); break; 
      case 3:imagepng($dest_img,(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."\r\n";
  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,2)),'g' => hexdec(substr($color,2,'b' => hexdec(substr($color,4,2))
  );
  } else {
  $r = substr($color,1) . substr($color,1);
  $g = substr($color,1,1);
  $b = substr($color,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示例代码如下：

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($flag){
echo '<img src="pic/'.basename($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','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',);

$obj = new PicThumb($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','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,透明度50 CMYK格式
$param = array(
'type' => 'crop','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';
}
?>

本文完整实例代码点击此处。

希望本文所述对大家的PHP程序设计有所帮助

版权声明：本文内容由互联网用户自发贡献，该文观点与技术仅代表作者本人。本站仅提供信息存储空间服务，不拥有所有权，不承担相关法律责任。如发现本站有涉嫌侵权/违法违规的内容， 请发送邮件至 [e-mail] 举报，一经查实，本站将立刻删除。