PHP教程
<?php  
//PHP 添加水印 & 比例縮略圖 & 固定高度 & 固定寬度 類. 
class Image_process{ 
  public $source; //原圖 
  public $source_width;  //原圖寬度 
  public $source_height; //原圖高度 
  public $source_type_id; 
  public $orign_name; 
  public $orign_dirname; 
    
  //傳入原圖路徑 
  public function __construct($source){ 
    $this->typeList = array(1=>'gif',2=>'jpg',3=>'png'); 
    $ginfo = getimagesize($source); 
    $this->source_width = $ginfo[0]; 
    $this->source_height = $ginfo[1]; 
    $this->source_type_id = $ginfo[2]; 
    $this->orign_url = $source; 
    $this->orign_name = basename($source); 
    $this->orign_dirname = dirname($source); 
  } 
    
  //判斷圖片的文件的格式,返回PHP可識別的編碼 
  public function judgeType($type,$source){ 
    if($type == 1){ 
      return imagecreatefromgif($source); //gif 
    }else if($type == 2){ 
      return imagecreatefromjpeg($source); //jpg 
    }else if($type == 3){ 
      return imagecreatefrompng($source); //png 
    }else{ 
      return false; 
    } 
  } 
    
  //生成水印圖片 
  public function waterMakeImage($logo){ 
    $linfo = getimagesize($logo); 
    $logo_width = $linfo[0]; 
    $logo_height = $linfo[1]; 
    $logo_type_id = $linfo[2]; 
    $sourceHandle = $this->judgeType($this->source_type_id,$this->orign_url); 
    $logoHandle = $this->judgeType($logo_type_id,$logo); 
    if(!$sourceHandle || !$logoHandle){ 
      return false; 
    } 
    $x = ($this->source_width - $logo_width)/2; 
    $y = ($this->source_height - $logo_height)/2; 
    imagecopy($sourceHandle,$logoHandle,$x,$y,0,0,$logo_width,$logo_height); 
    $newPic = $this->orign_dirname.'\water_'.time().'.'.$this->typeList[$this->source_type_id]; 
    if($this->saveImage($sourceHandle,$newPic)){ 
      imagedestroy($sourceHandle); 
      imagedestroy($logoHandle); 
    } 
  } 
    
  //固定高度寬度 
  public function fixSizeImage($width,$height){ 
    if($width > $this->source_width) $this->source_width; 
    if($height > $this->source_height) $this->source_height; 
    if($width === false){ 
      $width = floor($this->source_width / ($this->source_height / $height)); 
    } 
    if($height === false){ 
      $height = floor($this->source_height / ($this->source_width / $width)); 
    } 
    $this->tinyImage($width,$height); 
  } 
    
  //等比例縮放圖片 
  public function scaleImage($scale){ 
    $width = floor($this->source_width * $scale); 
    $height = floor($this->source_height * $scale); 
    $this->tinyImage($width, $height); 
  } 
    
  //創建縮略圖 
  public function tinyImage($width,$height){ 
    $tinyImage = imagecreatetruecolor($width,$height); 
    $handle = $this->judgeType($this->source_type_id,$this->orign_url); 
    if(function_exists('imagecopyresampled')){ 
      imagecopyresampled($tinyImage, $handle, 0, 0, 0, 0, $width, $height, $this->source_width, $this->source_height); 
    }else{ 
      imagecopyresized($tinyImage, $handle, 0, 0, 0, 0, $width, $height, $this->source_width, $this->source_height); 
    } 
    $newPic = $this->orign_dirname.'\thumb_'.time().'_'.$width."_".$height.".".$this->typeList[$this->source_type_id]; 
    if($this->saveImage($tinyImage,$newPic)){ 
      imagedestroy($tinyImage); 
      imagedestroy($handle); 
    } 
  } 
  //保存圖片 
  private function saveImage($image,$url){ 
    if(imagejpeg($image,$url)){ 
      return true; 
    } 
  } 
} 
$imgHandle = new Image_process('D:\AppServ\www\test\getimg\14061907445601.jpg'); 
//$imgHandle->waterMakeImage('D:\AppServ\www\test\getimg\shougongke.png');  //生成水印圖片 
//$imgHandle->fixSizeImage(200,150); //固定長度圖片 
$imgHandle->scaleImage(0.2); //等比例縮放 
?>

PHP教程
<?php
/**
 * 
 * 圖像處理類
 * @author FC_LAMP
 * @internal功能包含：水印,縮略圖
 */
class Img
{
 //圖片格式
 private $exts = array ('jpg', 'jpeg', 'gif', 'bmp', 'png' );
 /**
 * 
 * 
 * @throws Exception
 */
 public function __construct()
 {
 if (! function_exists ( 'gd_info' ))
 {
  throw new Exception ( '加載GD庫失敗!' );
 }
 }
 /**
 * 
 * 裁剪壓縮
 * @param $src_img 圖片
 * @param $save_img 生成后的圖片
 * @param $option 參數選項,包括： $maxwidth 寬 $maxheight 高
 * array('width'=>xx,'height'=>xxx)
 * @internal
 * 我們一般的壓縮圖片辦法,在圖片過長或過寬時生成的圖片
 * 都會被“壓扁”,針對這個應采用先裁剪后按比例壓縮的辦法
 */
 public function thumb_img($src_img, $save_img = '', $option)
 {
 if (empty ( $option ['width'] ) or empty ( $option ['height'] ))
 {
  return array ('flag' => False, 'msg' => '原圖長度與寬度不能小于0' );
 }
 $org_ext = $this->is_img ( $src_img );
 if (! $org_ext ['flag'])
 {
  return $org_ext;
 }
 //如果有保存路徑,則確定路徑是否正確
 if (! empty ( $save_img ))
 {
  $f = $this->check_dir ( $save_img );
  if (! $f ['flag'])
  {
  return $f;
  }
 }
 //獲取出相應的辦法
 $org_funcs = $this->get_img_funcs ( $org_ext ['msg'] );
 //獲取原大小
 $source = $org_funcs ['create_func'] ( $src_img );
 $src_w = imagesx ( $source );
 $src_h = imagesy ( $source );
 //調整原始圖像(保持圖片原形狀裁剪圖像)
 $dst_scale = $option ['height'] / $option ['width']; //目標圖像長寬比
 $src_scale = $src_h / $src_w; // 原圖長寬比
 if ($src_scale >= $dst_scale)
 { // 過高
  $w = intval ( $src_w );
  $h = intval ( $dst_scale * $w );
  $x = 0;
  $y = ($src_h - $h) / 3;
 } else
 { // 過寬
  $h = intval ( $src_h );
  $w = intval ( $h / $dst_scale );
  $x = ($src_w - $w) / 2;
  $y = 0;
 }
 // 剪裁
 $croped = imagecreatetruecolor ( $w, $h );
 imagecopy ( $croped, $source, 0, 0, $x, $y, $src_w, $src_h );
 // 縮放
 $scale = $option ['width'] / $w;
 $target = imagecreatetruecolor ( $option ['width'], $option ['height'] );
 $final_w = intval ( $w * $scale );
 $final_h = intval ( $h * $scale );
 imagecopyresampled ( $target, $croped, 0, 0, 0, 0, $final_w, $final_h, $w, $h );
 imagedestroy ( $croped );
 //輸出(保存)圖片
 if (! empty ( $save_img ))
 {
  $org_funcs ['save_func'] ( $target, $save_img );
 } else
 {
  header ( $org_funcs ['header'] );
  $org_funcs ['save_func'] ( $target );
 }
 imagedestroy ( $target );
 return array ('flag' => True, 'msg' => '' );
 }
 /**
 * 
 * 等比例縮放圖像
 * @param $src_img 原圖片
 * @param $save_img 需要保存的地方
 * @param $option 參數設置 array('width'=>xx,'height'=>xxx)
 * 
 */
 function resize_image($src_img, $save_img = '', $option)
 {
 $org_ext = $this->is_img ( $src_img );
 if (! $org_ext ['flag'])
 {
  return $org_ext;
 }
 //如果有保存路徑,則確定路徑是否正確
 if (! empty ( $save_img ))
 {
  $f = $this->check_dir ( $save_img );
  if (! $f ['flag'])
  {
  return $f;
  }
 }
 //獲取出相應的辦法
 $org_funcs = $this->get_img_funcs ( $org_ext ['msg'] );
 //獲取原大小
 $source = $org_funcs ['create_func'] ( $src_img );
 $src_w = imagesx ( $source );
 $src_h = imagesy ( $source );
 if (($option ['width'] && $src_w > $option ['width']) || ($option ['height'] && $src_h > $option ['height']))
 {
  if ($option ['width'] && $src_w > $option ['width'])
  {
  $widthratio = $option ['width'] / $src_w;
  $resizewidth_tag = true;
  }
  if ($option ['height'] && $src_h > $option ['height'])
  {
  $heightratio = $option ['height'] / $src_h;
  $resizeheight_tag = true;
  }
  if ($resizewidth_tag && $resizeheight_tag)
  {
  if ($widthratio < $heightratio)
   $ratio = $widthratio;
  else
   $ratio = $heightratio;
  }
  if ($resizewidth_tag && ! $resizeheight_tag)
  $ratio = $widthratio;
  if ($resizeheight_tag && ! $resizewidth_tag)
  $ratio = $heightratio;
  $newwidth = $src_w * $ratio;
  $newheight = $src_h * $ratio;
  if (function_exists ( "imagecopyresampled" ))
  {
  $newim = imagecreatetruecolor ( $newwidth, $newheight );
  imagecopyresampled ( $newim, $source, 0, 0, 0, 0, $newwidth, $newheight, $src_w, $src_h );
  } else
  {
  $newim = imagecreate ( $newwidth, $newheight );
  imagecopyresized ( $newim, $source, 0, 0, 0, 0, $newwidth, $newheight, $src_w, $src_h );
  }
 }
 //輸出(保存)圖片
 if (! empty ( $save_img ))
 {
  $org_funcs ['save_func'] ( $newim, $save_img );
 } else
 {
  header ( $org_funcs ['header'] );
  $org_funcs ['save_func'] ( $newim );
 }
 imagedestroy ( $newim );
 return array ('flag' => True, 'msg' => '' );
 }
 /**
 * 
 * 生成水印圖片
 * @param $org_img 原圖像
 * @param $mark_img 水印標記圖像
 * @param $save_img 當其目錄不存在時,會試著創建目錄
 * @param array $option 為水印的一些基本設置包含：
 * x:水印的水平位置,默認為減去水印圖寬度后的值
 * y:水印的垂直位置,默認為減去水印圖高度后的值
 * alpha:alpha值(控制透明度),默認為50
 */
 public function water_mark($org_img, $mark_img, $save_img = '', $option = array())
 {
 //檢查圖片
 $org_ext = $this->is_img ( $org_img );
 if (! $org_ext ['flag'])
 {
  return $org_ext;
 }
 $mark_ext = $this->is_img ( $mark_img );
 if (! $mark_ext ['flag'])
 {
  return $mark_ext;
 }
 //如果有保存路徑,則確定路徑是否正確
 if (! empty ( $save_img ))
 {
  $f = $this->check_dir ( $save_img );
  if (! $f ['flag'])
  {
  return $f;
  }
 }
 //獲取相應畫布
 $org_funcs = $this->get_img_funcs ( $org_ext ['msg'] );
 $org_img_im = $org_funcs ['create_func'] ( $org_img );
 $mark_funcs = $this->get_img_funcs ( $mark_ext ['msg'] );
 $mark_img_im = $mark_funcs ['create_func'] ( $mark_img );
 //拷貝水印圖片坐標
 $mark_img_im_x = 0;
 $mark_img_im_y = 0;
 //拷貝水印圖片高寬
 $mark_img_w = imagesx ( $mark_img_im );
 $mark_img_h = imagesy ( $mark_img_im );
 $org_img_w = imagesx ( $org_img_im );
 $org_img_h = imagesx ( $org_img_im );
 //合成生成點坐標
 $x = $org_img_w - $mark_img_w;
 $org_img_im_x = isset ( $option ['x'] ) ? $option ['x'] : $x;
 $org_img_im_x = ($org_img_im_x > $org_img_w or $org_img_im_x < 0) ? $x : $org_img_im_x;
 $y = $org_img_h - $mark_img_h;
 $org_img_im_y = isset ( $option ['y'] ) ? $option ['y'] : $y;
 $org_img_im_y = ($org_img_im_y > $org_img_h or $org_img_im_y < 0) ? $y : $org_img_im_y;
 //alpha
 $alpha = isset ( $option ['alpha'] ) ? $option ['alpha'] : 50;
 $alpha = ($alpha > 100 or $alpha < 0) ? 50 : $alpha;
 //合并圖片
 imagecopymerge ( $org_img_im, $mark_img_im, $org_img_im_x, $org_img_im_y, $mark_img_im_x, $mark_img_im_y, $mark_img_w, $mark_img_h, $alpha );
 //輸出(保存)圖片
 if (! empty ( $save_img ))
 {
  $org_funcs ['save_func'] ( $org_img_im, $save_img );
 } else
 {
  header ( $org_funcs ['header'] );
  $org_funcs ['save_func'] ( $org_img_im );
 }
 //銷毀畫布
 imagedestroy ( $org_img_im );
 imagedestroy ( $mark_img_im );
 return array ('flag' => True, 'msg' => '' );
 }
 /**
 * 
 * 檢查圖片
 * @param unknown_type $img_path
 * @return array('flag'=>true/false,'msg'=>ext/錯誤信息) 
 */
 private function is_img($img_path)
 {
 if (! file_exists ( $img_path ))
 {
  return array ('flag' => False, 'msg' => "加載圖片 $img_path 失敗!" );
 }
 $ext = explode ( '.', $img_path );
 $ext = strtolower ( end ( $ext ) );
 if (! in_array ( $ext, $this->exts ))
 {
  return array ('flag' => False, 'msg' => "圖片 $img_path 格式不正確!" );
 }
 return array ('flag' => True, 'msg' => $ext );
 }
 /**
 * 
 * 返回正確的圖片函數
 * @param unknown_type $ext
 */
 private function get_img_funcs($ext)
 {
 //選擇
 switch ($ext)
 {
  case 'jpg' :
  $header = 'Content-Type:image/jpeg';
  $createfunc = 'imagecreatefromjpeg';
  $savefunc = 'imagejpeg';
  break;
  case 'jpeg' :
  $header = 'Content-Type:image/jpeg';
  $createfunc = 'imagecreatefromjpeg';
  $savefunc = 'imagejpeg';
  break;
  case 'gif' :
  $header = 'Content-Type:image/gif';
  $createfunc = 'imagecreatefromgif';
  $savefunc = 'imagegif';
  break;
  case 'bmp' :
  $header = 'Content-Type:image/bmp';
  $createfunc = 'imagecreatefrombmp';
  $savefunc = 'imagebmp';
  break;
  default :
  $header = 'Content-Type:image/png';
  $createfunc = 'imagecreatefrompng';
  $savefunc = 'imagepng';
 }
 return array ('save_func' => $savefunc, 'create_func' => $createfunc, 'header' => $header );
 }
 /**
 * 
 * 檢查并試著創建目錄
 * @param $save_img
 */
 private function check_dir($save_img)
 {
 $dir = dirname ( $save_img );
 if (! is_dir ( $dir ))
 {
  if (! mkdir ( $dir, 0777, true ))
  {
  return array ('flag' => False, 'msg' => "圖片保存目錄 $dir 無法創建!" );
  }
 }
 return array ('flag' => True, 'msg' => '' );
 }
}
if (! empty ( $_FILES ['test'] ['tmp_name'] ))
{
 //例子
 $img = new Img ();
 //原圖
 $name = explode ( '.', $_FILES ['test'] ['name'] );
 $org_img = 'D:/test.' . end ( $name );
 move_uploaded_file ( $_FILES ['test'] ['tmp_name'], $org_img );
 $option = array ('width' => $_POST ['width'], 'height' => $_POST ['height'] );
 if ($_POST ['type'] == 1)
 {
 $s = $img->resize_image ( $org_img, '', $option );
 } else
 {
 $img->thumb_img ( $org_img, '', $option );
 }
 unlink ( $org_img );
}