PHP thumbnail and image watermark class (proportional scaling of image size)

/**
 *
 * Image processing class
 * @author FC_LAMP
 * @internal functions include: watermark, thumbnail
*/
class Img
{
 //Image format
 private $exts = array ('jpg', 'jpeg', 'gif ', 'bmp', 'png' );
 /**
  *
  *
  * @throws Exception
*/
 public function __construct()
 {
 if (! function_exists ( 'gd_info' ))
 {
 throw new Exception ( 'Loading GD library failed!' );
 }
 }
 /**
 *
 * Cropping and compression
 * @param $src_img picture
 * @param $save_img generated picture
 * @param $option parameter options, including: $maxwidth width $maxheight height
 * array('width'=> xx,'height'=>xxx)
 * @internal
 * General image compression method, when the image is too long or too wide, the generated image
 * will be "squashed". For this, crop first and then press Proportional compression method
*/
 public function thumb_img($src_img, $save_img = '', $option)
 {
  if (empty ( $option ['width'] ) or empty ( $option ['height'] ))
 {
 return array ('flag' => False, 'msg' => 'Original The length and width of the image cannot be less than 0' );
 }
 $org_ext = $this->is_img ( $src_img );
 if (! $org_ext ['flag'])
 {
 return $org_ext;
 }
 //If there is a save path, determine whether the path is correct
 if (! empty ( $save_img ))
 {
 $f = $this->check_dir ( $save_img );
 if ( ! $f ['flag'])
 {
 return $f;
 }
 }
 //Get the corresponding method
 $org_funcs = $this->get_img_funcs ( $org_ext ['msg'] );
 //Get the original size
 $source = $org_funcs ['create_func'] ( $src_img );
 $src_w = imagesx ( $source );
 $ src_h = imagesy ( $source );
 //Adjust the original image (keep the original shape of the image and crop the image)
 $dst_scale = $option ['height'] / $option ['width'] ; //Target image aspect ratio
 $src_scale = $src_h / $src_w; // Original image aspect ratio
 if ($src_scale >= $dst_scale)
 { // Too high
 $w = intval ( $src_w );
 $h = intval ( $dst_scale * $w );
 $x = 0;
 $y = ($src_h - $h) / 3;
 } else
 { / / Too wide
 $h = intval ( $src_h );
 $w = intval ( $h / $dst_scale );
 $x = ($src_w - $w) / 2;
 $y = 0;
 }
 // Crop
 $croped = imagecreatetruecolor ( $w, $h );
 imagecopy ( $croped, $source, 0, 0, $x, $y, $src_w, $src_h );
 // Scaling
 $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 );
 //Output (save) picture
 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' => '' );
 }
 /**
 *
 * Scale image
 * @param $src_img Original image
 * @param $save_img Where to save
 * @param $option Parameter setting array('width'=>xx,'height'=> xxx)
 *
*/
 function resize_image($src_img, $save_img = '', $option)
 {
 $org_ext = $this->is_img ( $src_img );
 if (! $org_ext ['flag'])
 {
 return $org_ext;
 }
  //If there is a save path, determine whether the path is correct
 if (! empty ( $save_img ))
 {
 $f = $this->check_dir ( $save_img );
 if (! $f [ 'flag'])
 {
 return $f;
 }
 }
 //Get the corresponding method
 $org_funcs = $this->get_img_funcs ( $org_ext ['msg' ] );
 //Get the original size
 $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  $ 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 );
   }
  }
  //输出(保存)图片
  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' => '' );
 }
 /**
 *
 * Generate watermark image
 * @param $org_img Original image
 * @param $mark_img Watermark image
 * @param $save_img When its directory does not exist, it will try to create the directory
 * @param array $option is Some basic settings of the watermark include:
 * x: the horizontal position of the watermark, the default is the value after subtracting the width of the watermark image
 * y: the vertical position of the watermark, the default is the value after subtracting the height of the watermark image
 * alpha: alpha Value (control transparency), default is 50
*/
 public function water_mark($org_img, $mark_img, $save_img = '', $option = array())
 {
  //检查图片
  $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;
  }
  //如果有保存路径，则确定路径是否正确
  if (! empty ( $save_img ))
  {
   $f = $this->check_dir ( $save_img );
   if (! $f ['flag'])
   {
    return $f;
   }
  }
  //获取相应画布
  $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 );
  //拷贝水印图片坐标
  $mark_img_im_x = 0;
  $mark_img_im_y = 0;
  //拷贝水印图片高宽
  $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 );
  //合成生成点坐标
  $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   $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
  //alpha
  $alpha = isset ( $option ['alpha'] ) ? $option ['alpha'] : 50;
  $alpha = ($alpha > 100 or $alpha
  //合并图片
  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 );
  //输出(保存)图片
  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 );
  }
  //销毁画布
  imagedestroy ( $org_img_im );
  imagedestroy ( $mark_img_im );
  return array ('flag' => True, 'msg' => '' );
 }
 /**
 *
 * Check the image
 * @param unknown_type $img_path
 * @return array('flag'=>true/false,'msg'=>ext/error message)
*/
 private function is_img($img_path)
 {
  if (! file_exists ( $img_path ))
  {
   return array ('flag' => False, 'msg' => "加载图片 $img_path 失败！" );
  }
  $ext = explode ( '.', $img_path );
  $ext = strtolower ( end ( $ext ) );
  if (! in_array ( $ext, $this->exts ))
  {
   return array ('flag' => False, 'msg' => "图片 $img_path 格式不正确！" );
  }
  return array ('flag' => True, 'msg' => $ext );
 }
 /**
 *
 * Return the correct image function
 * @param unknown_type $ext
*/
 private function get_img_funcs($ext)
 {
  //选择
  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 );
 }
 /**
 *
 * Check and try to create the directory
 * @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' => "图片保存目录 $dir 无法创建！" );
   }
  }
  return array ('flag' => True, 'msg' => '' );
 }
}
if (! empty ( $_FILES ['test'] ['tmp_name'] ))
{
 //例子
 $img = new Img ();
 //原图
 $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 );
}

使用方式： php水印

$img = new Img ();
$org_img = 'D:/tt.png';
$mark_img = 'D:/t.png';
//保存水印图片(如果$save_img为空时，将会直接输出图片)
$save_img = 'D:/test99h/testone/sss.png';
//水印设置调节
$option = array ('x' => 50, 'y' => 50, 'alpha' => 80 );
//生成水印图片
$flag = $img->water_mark ( $org_img, $mark_img, $save_img, $option );

当调节 $option 参数时，会有相应变化：

//例子
$img = new Img ();
$org_img = 'D:/tt.png';
//压缩图片(100*100)
$option = array ('width' => 100, 'height' => 100 );
//$save_img为空时，将会直接输出图像到浏览器
$save_img = 'D:/test99h/testone/sss_thumb.png';
$flag = $img->thumb_img ( $org_img, $save_img, $option );

调节$option的大小值：

$img = new Img ();
//原图
$org_img = 'D:/tt.png';
//水印标记图
$mark_img = 'D:/t.png';
//保存水印图片
$save_img = 'D:/test99h/testone/sss.png';
//水印设置调节
$option = array ('x' => 50, 'y' => 50, 'alpha' => 60 );
//生成水印图片
$flag = $img->water_mark ( $org_img, $mark_img, $save_img, $option );
//压缩水印图片
$option = array ('width' => 200, 'height' => 200 );
//保存压缩图
$save_img2 = 'D:/test99h/testone/sss2_thumb.png';
$flag = $img->thumb_img ( $save_img, $save_img2, $option ); //等比例压缩类似

在压缩生成的水印图像时，压缩后生成的图像格式应与原图像，水印图像一致。 不然，会出现一些未知错误。