php将图片保存为不同尺寸图片的图片类实例，_PHP教程

<&#63;php
/**
  图片处理类
 */
class imagecls
{
  /**
   * 文件信息
   */
  var $file = array();
  /**
   * 保存目录
   */
  var $dir = '';
  /**
   * 错误代码
   */
  var $error_code = 0;
  /**
   * 文件上传最大KB
   */
  var $max_size = -1;
  function es_imagecls()
  {
  }
  private function checkSize($size)
  {
    return !($size > $this->max_size) || (-1 == $this->max_size);
  }
  /**
   * 处理上传文件
   * @param array $file 上传的文件
   * @param string $dir 保存的目录
   * @return bool
   */
  function init($file, $dir = 'temp')
  {
    if(!is_array($file) || empty($file) || !$this->isUploadFile($file['tmp_name']) || trim($file['name']) == '' || $file['size'] == 0)
    {
      $this->file = array();
      $this->error_code = -1;
      return false;
    }
    else
    {
      $file['size'] = intval($file['size']);
      $file['name'] = trim($file['name']);
      $file['thumb'] = '';
      $file['ext'] = $this->fileExt($file['name']);
      $file['name'] = htmlspecialchars($file['name'], ENT_QUOTES);
      $file['is_image'] = $this->isImageExt($file['ext']);
      $file['file_dir'] = $this->getTargetDir($dir);
      $file['prefix'] = md5(microtime(true)).rand(10,99);
      $file['target'] = "./public/".$file['file_dir'].'/'.$file['prefix'].'.jpg'; //相对
      $file['local_target'] = APP_ROOT_PATH."public/".$file['file_dir'].'/'.$file['prefix'].'.jpg'; //物理
      $this->file = &$file;
      $this->error_code = 0;
      return true;
    }
  }
  /**
   * 保存文件
   * @return bool
   */
  function save()
  {
    if(empty($this->file) || empty($this->file['tmp_name']))
      $this->error_code = -101;
    elseif(!$this->checkSize($this->file['size']))
      $this->error_code = -105;
    elseif(!$this->file['is_image'])
      $this->error_code = -102;
    elseif(!$this->saveFile($this->file['tmp_name'], $this->file['local_target']))
      $this->error_code = -103;
    elseif($this->file['is_image'] && (!$this->file['image_info'] = $this->getImageInfo($this->file['local_target'], true)))
    {
      $this->error_code = -104;
      @unlink($this->file['local_target']);
    }
    else
    {
      $this->error_code = 0;
      return true;
    }
    return false;
  }
  /**
   * 获取错误代码
   * @return number
   */
  function error()
  {
    return $this->error_code;
  }
  /**
   * 获取文件扩展名
   * @return string
   */
  function fileExt($file_name)
  {
    return addslashes(strtolower(substr(strrchr($file_name, '.'), 1, 10)));
  }
  /**
   * 根据扩展名判断文件是否为图像
   * @param string $ext 扩展名
   * @return bool
   */
  function isImageExt($ext)
  {
    static $img_ext = array('jpg', 'jpeg', 'png', 'bmp','gif','giff');
    return in_array($ext, $img_ext) &#63; 1 : 0;
  }
  /**
   * 获取图像信息
   * @param string $target 文件路径
   * @return mixed
   */
  function getImageInfo($target)
  {
    $ext = es_imagecls::fileExt($target);
    $is_image = es_imagecls::isImageExt($ext);
    if(!$is_image)
      return false;
    elseif(!is_readable($target))
      return false;
    elseif($image_info = @getimagesize($target))
    {
      list($width, $height, $type) = !empty($image_info) &#63; $image_info : array('', '', '');
      $size = $width * $height;
      if($is_image && !in_array($type, array(1,2,3,6,13)))
        return false;
      $image_info['type'] = strtolower(substr(image_type_to_extension($image_info[2]),1));
      return $image_info;
    }
    else
      return false;
  }
  /**
   * 获取是否充许上传文件
   * @param string $source 文件路径
   * @return bool
   */
  function isUploadFile($source)
  {
    return $source && ($source != 'none') && (is_uploaded_file($source) || is_uploaded_file(str_replace('\\\\', '\\', $source)));
  }
  /**
   * 获取保存的路径
   * @param string $dir 指定的保存目录
   * @return string
   */
  function getTargetDir($dir)
  {    
    if (!is_dir(APP_ROOT_PATH."public/".$dir)) {
       @mkdir(APP_ROOT_PATH."public/".$dir);
       @chmod(APP_ROOT_PATH."public/".$dir, 0777);
    }
    return $dir;
  }
  /**
   * 保存文件
   * @param string $source 源文件路径
   * @param string $target 目录文件路径
   * @return bool
   */
  private function saveFile($source, $target)
  {
    if(!es_imagecls::isUploadFile($source))
      $succeed = false;
    elseif(@copy($source, $target))
      $succeed = true;
    elseif(function_exists('move_uploaded_file') && @move_uploaded_file($source, $target))
      $succeed = true;
    elseif (@is_readable($source) && (@$fp_s = fopen($source, 'rb')) && (@$fp_t = fopen($target, 'wb')))
    {
      while (!feof($fp_s))
      {
        $s = @fread($fp_s, 1024 * 512);
        @fwrite($fp_t, $s);
      }
      fclose($fp_s);
      fclose($fp_t);
      $succeed = true;
    }
    if($succeed)
    {
      $this->error_code = 0;
      @chmod($target, 0644);
      @unlink($source);
    }
    else
    {
      $this->error_code = 0;
    }
    return $succeed;
  }
  public function thumb($image,$maxWidth=200,$maxHeight=50,$gen = 0,$interlace=true,$filepath = '',$is_preview = true)
  {
    $info = es_imagecls::getImageInfo($image);
    if($info !== false)
    {
      $srcWidth = $info[0];
      $srcHeight = $info[1];
      $type = $info['type'];
      $interlace = $interlace&#63; 1:0;
      unset($info);
      if($maxWidth > 0 && $maxHeight > 0)
        $scale = min($maxWidth/$srcWidth, $maxHeight/$srcHeight); // 计算缩放比例
      elseif($maxWidth == 0)
        $scale = $maxHeight/$srcHeight;
      elseif($maxHeight == 0)
        $scale = $maxWidth/$srcWidth;
      $paths = pathinfo($image);
      $paths['filename'] = trim(strtolower($paths['basename']),".".strtolower($paths['extension']));
      $basefilename = explode("_",$paths['filename']);
      $basefilename = $basefilename[0];
      if(empty($filepath))
      {
        if($is_preview)
        $thumbname = $paths['dirname'].'/'.$basefilename.'_'.$maxWidth.'x'.$maxHeight.'.jpg';
        else
        $thumbname = $paths['dirname'].'/'.$basefilename.'o_'.$maxWidth.'x'.$maxHeight.'.jpg';
      }
      else
        $thumbname = $filepath;
      $thumburl = str_replace(APP_ROOT_PATH,'./',$thumbname);
      if($scale >= 1)
      {
        // 超过原图大小不再缩略
        $width  = $srcWidth;
        $height = $srcHeight;    
        if(!$is_preview)
        {   
          //非预览模式写入原图
          file_put_contents($thumbname,file_get_contents($image));  //用原图写入      
          return array('url'=>$thumburl,'path'=>$thumbname);
        }
      }
      else
      {
        // 缩略图尺寸
        $width = (int)($srcWidth*$scale);
        $height = (int)($srcHeight*$scale);
      }   
      if($gen == 1)
      {
        $width = $maxWidth;
        $height = $maxHeight;
      }
      // 载入原图
      $createFun = 'imagecreatefrom'.($type=='jpg'&#63;'jpeg':$type);
      if(!function_exists($createFun))
        $createFun = 'imagecreatefromjpeg';
      $srcImg = $createFun($image);
      //创建缩略图
      if($type!='gif' && function_exists('imagecreatetruecolor'))
        $thumbImg = imagecreatetruecolor($width, $height);
      else
        $thumbImg = imagecreate($width, $height);
      $x = 0;
      $y = 0;
      if($gen == 1 && $maxWidth > 0 && $maxHeight > 0)
      {
        $resize_ratio = $maxWidth/$maxHeight;
        $src_ratio = $srcWidth/$srcHeight;
        if($src_ratio >= $resize_ratio)
        {
          $x = ($srcWidth - ($resize_ratio * $srcHeight)) / 2;
          $width = ($height * $srcWidth) / $srcHeight;
        }
        else
        {
          $y = ($srcHeight - ( (1 / $resize_ratio) * $srcWidth)) / 2;
          $height = ($width * $srcHeight) / $srcWidth;
        }
      }
      // 复制图片
      if(function_exists("imagecopyresampled"))
        imagecopyresampled($thumbImg, $srcImg, 0, 0, $x, $y, $width, $height, $srcWidth,$srcHeight);
      else
        imagecopyresized($thumbImg, $srcImg, 0, 0, $x, $y, $width, $height, $srcWidth,$srcHeight);
      if('gif'==$type || 'png'==$type) {
        $background_color = imagecolorallocate($thumbImg, 0,255,0); // 指派一个绿色
        imagecolortransparent($thumbImg,$background_color); // 设置为透明色，若注释掉该行则输出绿色的图
      }
      // 对jpeg图形设置隔行扫描
      if('jpg'==$type || 'jpeg'==$type)
        imageinterlace($thumbImg,$interlace);
      // 生成图片
      imagejpeg($thumbImg,$thumbname,100);
      imagedestroy($thumbImg);
      imagedestroy($srcImg);
      return array('url'=>$thumburl,'path'=>$thumbname);
     }
     return false;
  }
  public function make_thumb($srcImg,$srcWidth,$srcHeight,$type,$maxWidth=200,$maxHeight=50,$gen = 0)
  {
      $interlace = $interlace&#63; 1:0;
      if($maxWidth > 0 && $maxHeight > 0)
        $scale = min($maxWidth/$srcWidth, $maxHeight/$srcHeight); // 计算缩放比例
      elseif($maxWidth == 0)
        $scale = $maxHeight/$srcHeight;
      elseif($maxHeight == 0)
        $scale = $maxWidth/$srcWidth;
      if($scale >= 1)
      {
        // 超过原图大小不再缩略
        $width  = $srcWidth;
        $height = $srcHeight;
      }
      else
      {
        // 缩略图尺寸
        $width = (int)($srcWidth*$scale);
        $height = (int)($srcHeight*$scale);
      }
      if($gen == 1)
      {
        $width = $maxWidth;
        $height = $maxHeight;
      }
      //创建缩略图
      if($type!='gif' && function_exists('imagecreatetruecolor'))
        $thumbImg = imagecreatetruecolor($width, $height);
      else
        $thumbImg = imagecreatetruecolor($width, $height);
      $x = 0;
      $y = 0;
      if($gen == 1 && $maxWidth > 0 && $maxHeight > 0)
      {
        $resize_ratio = $maxWidth/$maxHeight;
        $src_ratio = $srcWidth/$srcHeight;
        if($src_ratio >= $resize_ratio)
        {
          $x = ($srcWidth - ($resize_ratio * $srcHeight)) / 2;
          $width = ($height * $srcWidth) / $srcHeight;
        }
        else
        {
          $y = ($srcHeight - ( (1 / $resize_ratio) * $srcWidth)) / 2;
          $height = ($width * $srcHeight) / $srcWidth;
        }
      }
      // 复制图片
      if(function_exists("imagecopyresampled"))
        imagecopyresampled($thumbImg, $srcImg, 0, 0, $x, $y, $width, $height, $srcWidth,$srcHeight);
      else
        imagecopyresized($thumbImg, $srcImg, 0, 0, $x, $y, $width, $height, $srcWidth,$srcHeight);
      if('gif'==$type || 'png'==$type) {
        $background_color = imagecolorallocate($thumbImg, 255,255,255); // 指派一个绿色
        imagecolortransparent($thumbImg,$background_color); // 设置为透明色，若注释掉该行则输出绿色的图
      }
      // 对jpeg图形设置隔行扫描
      if('jpg'==$type || 'jpeg'==$type)
        imageinterlace($thumbImg,$interlace);
      return $thumbImg;
  }
  public function water($source,$water,$alpha=80,$position="0")
  {
    //检查文件是否存在
    if(!file_exists($source)||!file_exists($water))
      return false;
    //图片信息
    $sInfo = es_imagecls::getImageInfo($source);
    $wInfo = es_imagecls::getImageInfo($water);
    //如果图片小于水印图片，不生成图片
    if($sInfo["0"] < $wInfo["0"] || $sInfo['1'] < $wInfo['1'])
      return false;
    if(is_animated_gif($source))
    {
      require_once APP_ROOT_PATH."system/utils/gif_encoder.php";
      require_once APP_ROOT_PATH."system/utils/gif_reader.php";
      $gif = new GIFReader();
      $gif->load($source);
      foreach($gif->IMGS['frames'] as $k=>$img)
      {
        $im = imagecreatefromstring($gif->getgif($k));   
        //为im加水印
        $sImage=$im;    
        $wCreateFun="imagecreatefrom".$wInfo['type'];
        if(!function_exists($wCreateFun))
          $wCreateFun = 'imagecreatefromjpeg';
        $wImage=$wCreateFun($water);
        //设定图像的混色模式
        imagealphablending($wImage, true);   
        switch (intval($position))
        {
          case 0: break;
          //左上
          case 1:
            $posY=0;
            $posX=0;
            //生成混合图像
            imagecopymerge($sImage, $wImage, $posX, $posY, 0, 0, $wInfo[0],$wInfo[1],$alpha);
            break;
          //右上
          case 2:
            $posY=0;
            $posX=$sInfo[0]-$wInfo[0];
            //生成混合图像
            imagecopymerge($sImage, $wImage, $posX, $posY, 0, 0, $wInfo[0],$wInfo[1],$alpha);
            break;
          //左下
          case 3:
            $posY=$sInfo[1]-$wInfo[1];
            $posX=0;
            //生成混合图像
            imagecopymerge($sImage, $wImage, $posX, $posY, 0, 0, $wInfo[0],$wInfo[1],$alpha);
            break;
          //右下
          case 4:
            $posY=$sInfo[1]-$wInfo[1];
            $posX=$sInfo[0]-$wInfo[0];
            //生成混合图像
            imagecopymerge($sImage, $wImage, $posX, $posY, 0, 0, $wInfo[0],$wInfo[1],$alpha);
            break;
          //居中
          case 5:
            $posY=$sInfo[1]/2-$wInfo[1]/2;
            $posX=$sInfo[0]/2-$wInfo[0]/2;
            //生成混合图像
            imagecopymerge($sImage, $wImage, $posX, $posY, 0, 0, $wInfo[0],$wInfo[1],$alpha);
            break;
        }
        //end im加水印
        ob_start();
        imagegif($sImage);
        $content = ob_get_contents();
        ob_end_clean();
        $frames [ ] = $content;
        $framed [ ] = $img['frameDelay'];
      }
      $gif_maker = new GIFEncoder (
          $frames,
          $framed,
          0,
          2,
          0, 0, 0,
          "bin"  //bin为二进制  url为地址
       );
      $image_rs = $gif_maker->GetAnimation ( );
      //如果没有给出保存文件名，默认为原图像名
      @unlink($source);
      //保存图像
      file_put_contents($source,$image_rs);
      return true;
    } 
    //建立图像
    $sCreateFun="imagecreatefrom".$sInfo['type'];
    if(!function_exists($sCreateFun))
      $sCreateFun = 'imagecreatefromjpeg';
    $sImage=$sCreateFun($source);
    $wCreateFun="imagecreatefrom".$wInfo['type'];
    if(!function_exists($wCreateFun))
      $wCreateFun = 'imagecreatefromjpeg';
    $wImage=$wCreateFun($water);
    //设定图像的混色模式
    imagealphablending($wImage, true);
    switch (intval($position))
    {
      case 0: break;
      //左上
      case 1:
        $posY=0;
        $posX=0;
        //生成混合图像
        imagecopymerge($sImage, $wImage, $posX, $posY, 0, 0, $wInfo[0],$wInfo[1],$alpha);
        break;
      //右上
      case 2:
        $posY=0;
        $posX=$sInfo[0]-$wInfo[0];
        //生成混合图像
        imagecopymerge($sImage, $wImage, $posX, $posY, 0, 0, $wInfo[0],$wInfo[1],$alpha);
        break;
      //左下
      case 3:
        $posY=$sInfo[1]-$wInfo[1];
        $posX=0;
        //生成混合图像
        imagecopymerge($sImage, $wImage, $posX, $posY, 0, 0, $wInfo[0],$wInfo[1],$alpha);
        break;
      //右下
      case 4:
        $posY=$sInfo[1]-$wInfo[1];
        $posX=$sInfo[0]-$wInfo[0];
        //生成混合图像
        imagecopymerge($sImage, $wImage, $posX, $posY, 0, 0, $wInfo[0],$wInfo[1],$alpha);
        break;
      //居中
      case 5:
        $posY=$sInfo[1]/2-$wInfo[1]/2;
        $posX=$sInfo[0]/2-$wInfo[0]/2;
        //生成混合图像
        imagecopymerge($sImage, $wImage, $posX, $posY, 0, 0, $wInfo[0],$wInfo[1],$alpha);
        break;
    }
    //如果没有给出保存文件名，默认为原图像名
    @unlink($source);
    //保存图像
    imagejpeg($sImage,$source,100);
    imagedestroy($sImage);
  }
}
if(!function_exists('image_type_to_extension'))
{
  function image_type_to_extension($imagetype)
  {
    if(empty($imagetype))
      return false;
    switch($imagetype)
    {
      case IMAGETYPE_GIF  : return '.gif';
      case IMAGETYPE_JPEG  : return '.jpeg';
      case IMAGETYPE_PNG  : return '.png';
      case IMAGETYPE_SWF  : return '.swf';
      case IMAGETYPE_PSD  : return '.psd';
      case IMAGETYPE_BMP  : return '.bmp';
      case IMAGETYPE_TIFF_II : return '.tiff';
      case IMAGETYPE_TIFF_MM : return '.tiff';
      case IMAGETYPE_JPC  : return '.jpc';
      case IMAGETYPE_JP2  : return '.jp2';
      case IMAGETYPE_JPX  : return '.jpf';
      case IMAGETYPE_JB2  : return '.jb2';
      case IMAGETYPE_SWC  : return '.swc';
      case IMAGETYPE_IFF  : return '.aiff';
      case IMAGETYPE_WBMP  : return '.wbmp';
      case IMAGETYPE_XBM  : return '.xbm';
      default        : return false;
    }
  }
}
&#63;>

//获取相应规格的图片地址 
//gen=0:保持比例缩放，不剪裁,如高为0，则保证宽度按比例缩放 gen=1：保证长宽，剪裁 
function get_spec_image($img_path,$width=0,$height=0,$gen=0,$is_preview=true) 
{ 
  if($width==0) 
    $new_path = $img_path; 
  else 
  { 
    $img_name = substr($img_path,0,-4); 
    $img_ext = substr($img_path,-3);   
    if($is_preview) 
    $new_path = $img_name."_".$width."x".$height.".jpg";   
    else 
    $new_path = $img_name."o_".$width."x".$height.".jpg";  
    if(!file_exists($new_path)) 
    { 
      require_once "imagecls.php"; 
      $imagec = new imagecls(); 
      $thumb = $imagec->thumb($img_path,$width,$height,$gen,true,"",$is_preview); 
      if(app_conf("PUBLIC_DOMAIN_ROOT")!='') 
      { 
        $paths = pathinfo($new_path); 
        $path = str_replace("./","",$paths['dirname']); 
        $filename = $paths['basename']; 
        $pathwithoupublic = str_replace("public/","",$path); 
            $file_data = @file_get_contents($path.$file); 
            $img = @imagecreatefromstring($file_data); 
            if($img!==false) 
            { 
              $save_path = "public/".$path; 
              if(!is_dir($save_path)) 
              { 
                @mk_dir($save_path);       
              } 
              @file_put_contents($save_path.$name,$file_data); 
            } 
      } 
    } 
  } 
  return $new_path; 
}

//im:将店铺图片保存为3种规格:小图:48x48,中图120x120,大图200x200
$small_url=get_spec_image($data['image'],48,48,0);
$<span id="result_box" class="short_text" lang="en"><span>middle_url</span></span>=get_spec_image($data['image'],120,120,0);
$big_url=get_spec_image($data['image'],200,200,0);