php 将图片保存为不同尺寸的图片类的简单示例

对一个php图片类，将图片保存为不同尺寸的图片感兴趣的小伙伴，下面一起跟随编程之家 jb51.cc的小编两巴掌来看看吧！

<?php
/**
 * 一个php图片类，将图片保存为不同尺寸的图片
 *
 * @param 
 * @arrange 网： www.www.jb51.cc
 **/
/**
 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) ? 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) ? $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  =  $interlace? 1:0;
			unset($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'?'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,$srcImg,$x,$y,$width,$srcWidth,$srcHeight);
			else
				imagecopyresized($thumbImg,$srcHeight);
			if('gif'==$type || 'png'==$type) {
				$background_color  =  imagecolorallocate($thumbImg,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($srcImg,$srcHeight,$type,$gen = 0)
	{
			$interlace  =  $interlace? 1:0;
   if($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,255);  //  指派一个绿色
	imagecolortransparent($thumbImg,$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,$posY,$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,$alpha);
			break;
		   //左下
		   case 3:
			$posY=$sInfo[1]-$wInfo[1];
			$posX=0;
			//生成混合图像
			imagecopymerge($sImage,$alpha);
			break;
		   //右下
		   case 4:
			$posY=$sInfo[1]-$wInfo[1];
			$posX=$sInfo[0]-$wInfo[0];
			//生成混合图像
			imagecopymerge($sImage,$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,$alpha);
			break;
		  }
	//end im加水印
	ob_start();
	imagegif($sImage);
	$content = ob_get_contents();
		  ob_end_clean();
	$frames [ ] = $content;
	   $framed [ ] = $img['frameDelay'];
   }
   $gif_maker = new GIFEncoder (
		  $frames,$framed,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,$alpha);
		  break;
		 //右上
		 case 2:
		  $posY=0;
		  $posX=$sInfo[0]-$wInfo[0];
		  //生成混合图像
		  imagecopymerge($sImage,$alpha);
		  break;
		 //左下
		 case 3:
		  $posY=$sInfo[1]-$wInfo[1];
		  $posX=0;
		  //生成混合图像
		  imagecopymerge($sImage,$alpha);
		  break;
		 //右下
		 case 4:
		  $posY=$sInfo[1]-$wInfo[1];
		  $posX=$sInfo[0]-$wInfo[0];
		  //生成混合图像
		  imagecopymerge($sImage,$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,$alpha);
		  break;
		}
		//如果没有给出保存文件名，默认为原图像名
		@unlink($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;
  }
 }
}

/***   来自编程之家 jb51.cc（jb51.cc）   ***/