php 將圖片保存為不同規格的圖片

 1.圖片處理類.imagecls.php

<?php
/**
	圖片處理類
 */
class imagecls
{
	/**
	 * 文件信息
	 */
	var $file = array();
	/**
	 * 保存目錄
	 */
	var $dir = '';
	/**
	 * 錯誤代碼
	 */
	var $error_code = 0;
	/**
	 * 文件上傳最大KB
	 */
	var $max_size = -1;

	function es_imagecls()
	{

	}
	
    private function checkSize($size)
    {
        return !($size > $this->max_size) || (-1 == $this->max_size);
    }
    
	/**
	 * 處理上傳文件
	 * @param array $file 上傳的文件
	 * @param string $dir 保存的目錄
	 * @return bool
	 */
	function init($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';  //相對
$file['local_target'] = APP_ROOT_PATH."public/".$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;
	}

	/**
	 * 獲取錯誤代碼
	 * @return number
	 */
	function error()
	{
		return $this->error_code;
	}

	/**
	 * 獲取文件擴展名
	 * @return string
	 */
	function fileExt($file_name)
	{
		return addslashes(strtolower(substr(strrchr($file_name, '.'), 1, 10)));
	}

	/**
	 * 根據擴展名判斷文件是否為圖像
	 * @param string $ext 擴展名
	 * @return bool
	 */
	function isImageExt($ext)
	{
		static $img_ext  = array('jpg', 'jpeg', 'png', 'bmp','gif','giff');
		return in_array($ext, $img_ext) ? 1 : 0;
	}

	/**
	 * 獲取圖像信息
	 * @param string $target 文件路徑
	 * @return mixed
	 */
	function getImageInfo($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;
	}

	/**
	 * 獲取是否充許上傳文件
	 * @param string $source 文件路徑
	 * @return bool
	 */
	function isUploadFile($source)
	{
		return $source && ($source != 'none') && 
          (is_uploaded_file($source) || is_uploaded_file(str_replace('', '', $source)));
	}

	/**
	 * 獲取保存的路徑
	 * @param string $dir 指定的保存目錄
	 * @return string
	 */
	function getTargetDir($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 源文件路徑
	 * @param string $target 目錄文件路徑
	 * @return bool
	 */
	private function saveFile($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); 
                                // 計算縮放比例
			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)
			{
                // 超過原圖大小不再縮略
                $width   =  $srcWidth;
                $height  =  $srcHeight;         
                if(!$is_preview)
                {       
                	//非預覽模式寫入原圖
                	file_put_contents($thumbname,file_get_contents($image));    //用原圖寫入            
                	return array('url'=>$thumburl,'path'=>$thumbname);
                }
            }
			else
			{
                // 縮略圖尺寸
                $width  = (int)($srcWidth*$scale);
                $height = (int)($srcHeight*$scale);
            }		
			
			if($gen == 1)
			{
				$width = $maxWidth;
				$height = $maxHeight;
			}

            // 載入原圖
            $createFun = 'imagecreatefrom'.($type=='jpg'?'jpeg':$type);
			if(!function_exists($createFun))
				$createFun = 'imagecreatefromjpeg';

            $srcImg = $createFun($image);

            //創建縮略圖
            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 = $maxWidth/$maxHe