php生成图片缩略图方法收集

<p><?php</p>/*<br />*php生成图片缩略图的函数<br />*www.scutephp.com<br />*/<br />function thumbImage($file,$thumbWidth,$thumbHeight,$savePath='',$isCut=true,$quality=100){<br />    $result=array('status'=>0,'file'=>'','width'=>0,'height'=>0,'savePath'=>'','info'=>'');<br />   if(!file_exists($file)){<br />        return array('status'=>1,'file'=>'','width'=>0,'height'=>0,'savePath'=>'','info'=>'图片文件不存在');<br /> }<br />   //检测文件类型<br />    $fp=fopen($file,'rb');<br />  $str=fread($fp,2); //只读2字节<br />  fclose($fp);<br />    $str=@unpack("c2chars",$str);<br />   $typeCode=intval($str['chars1'].$str['chars2']);<br />    $fileType='';<br />   switch($typeCode){<br />      case 255216:<br />            $fileType='jpg';<br />        break;<br />      case 7173:<br />          $fileType='gif';<br />        break;<br />      case 6677:<br />          $fileType='bmp';<br />        break;<br />      case 13780:<br />         $fileType='png';<br />        break;<br />      default:<br />            $fileType=$typeCode;<br />        break;<br />  }<br />   if($str['chars1']=='-1'&&$str['chars2']=='-40'){<br />        $fileType='jpg';<br />    }<br />   if($str['chars1']=='-119'&&$str['chars2']=='80'){<br />       $fileType='png';<br />    }<br />   if(!in_array($fileType,array('jpg','gif','bmp','png'))){<br />        return array('status'=>2,'file'=>'','width'=>0,'height'=>0,'savePath'=>'','info'=>'图片文件类型不正确:'.$fileType);<br />    }<br />   //图片缩放处理<br />    if($fileType=='jpg'){<br />       $im=imagecreatefromjpeg($file);<br /> }<br />   if($fileType=='gif'){<br />       $im=imagecreatefromgif($file);<br />  }<br />   if($fileType=='png'){<br />       $im=imagecreatefrompng($file);<br />  }<br />   if(empty($savePath))<br />    $savePath=$file;<br />    $width=imagesx($im);<br />    $height=imagesy($im);<br />   if($width<$thumbWidth&&$height<$thumbHeight){<br />     return array('status'=>3,'file'=>'','width'=>0,'height'=>0,'savePath'=>'','info'=>'图片尺寸小于生成缩略图的尺寸');<br />  }<br />   $ratio=$width/$height;//实际图象的比例<br /> $thumbRatio=$thumbWidth/$thumbHeight;//改变后的图象的比例<br />    if($isCut){//裁切处理<br />       if(function_exists('imagepng')&&(str_replace('.','',PHP_VERSION)>=512)){//针对php版本大于5.12参数变化后的处理情况<br />            $quality=9;<br />     }<br />       if($ratio>=$thumbRatio){//高度优先<br />           $newimg=imagecreatetruecolor($thumbWidth,$thumbHeight);<br />         imagecopyresampled($newimg,$im,0,0,0,0,$thumbWidth,$thumbHeight,(($height)*$thumbRatio),$height);<br />           imagejpeg($newimg,$savePath,$quality);<br />      }<br />       if($ratio<$thumbRatio){//宽度优先<br />            $newimg=imagecreatetruecolor($thumbWidth,$thumbHeight);<br />         imagecopyresampled($newimg,$im,0,0,0,0,$thumbWidth,$thumbHeight,$width,(($width)/$thumbRatio));<br />         imagejpeg($newimg,$savePath,$quality);<br />      }<br />   }else{//不裁切处理<br />       if($ratio>=$thumbRatio){<br />         $newimg=imagecreatetruecolor($thumbWidth,($thumbWidth)/$ratio);<br />         imagecopyresampled($newimg,$im,0,0,0,0,$thumbWidth,($thumbWidth)/$ratio,$width,$height);<br />            imagejpeg($newimg,$savePath,$quality);<br />      }<br />       if($ratio<$thumbRatio){<br />          $newimg=imagecreatetruecolor(($thumbHeight)*$ratio,$thumbHeight);<br />           imagecopyresampled($newimg,$im,0,0,0,0,($thumbHeight)*$ratio,$thumbHeight,$width,$height);<br />          imagejpeg($newimg,$savePath,$quality);<br />      }<br />   }<br />   ImageDestroy($im);//www.scutephp.com/php-function/1007.html<br /> return array('status'=>0,'file'=>$file,'width'=>$thumbWidth,'height'=>$thumbHeight,'savePath'=>$savePath,'info'=>'缩略图片生成成功');<br /><p>}

$a=thumbImage('1.jpg',200,100,'2.jpg');//将1.jpg生成宽为200，高为100的缩略图，并保存为2.jpg<br />print_r($a);