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);