PHP -- HOw to Resize a JPG Image proportionately on upload function..

<?php // RAY_upload.php UPLOAD AN IMAGE AND RESIZE IT TO FIT A PREDEFINED SIZE
 
 
// A FUNCTION TO DETERMINE IF GD IS AT LEVEL 2 OR MORE
function get_gd_info($display=FALSE)
{
 
// IS GD INSTALLED AT ALL?
   if (!function_exists("gd_info"))
   {
      if ($display) echo "<br/>GD NOT INSTALLED\n";
      return FALSE;
   }
 
// IF GD IS INSTALLED GET DETAILS
   $gd = gd_info();
 
// IF DISPLAY IS REQUESTED, PRINT DETAILS
   if ($display)
   {
      echo "<br/>GD DETAILS:\n";
      foreach ($gd as $key => $value)
      {
         if ($value === TRUE)  $value = 'YES';
         if ($value === FALSE) $value = 'NO';
         echo "<br/>$key = $value \n";
      }
   }
 
// RETURN THE VERSION NUMBER
   $gd_version = ereg_replace('[^0-9\.]', '', $gd["GD Version"]);;
   return $gd_version;
}
 
 
// A FUNCTION TO MAKE AN IMAGE INTO THE RIGHT WIDTH FOR PAGE DISPLAY
// WILL WORK IF GD2 NOT INSTALLED, BUT WILL MAKE BETTER IMAGES WITH GD2
// INPUT IS THE IMAGE FILE NAME, OUTPUT IS AN IMAGE RESOURCE, OR FALSE IF NO RESIZE NEEDED
function create_right_size_image($image, $width=720)
{
// IS GD HERE?
   $gdv = get_gd_info();
   if (!$gdv) return FALSE;
 
// GET AN IMAGE THING
   $source = imagecreatefromjpeg("$image");
 
// GET THE X AND Y DIMENSIONS
   $imageX = imagesx($source);
   $imageY = imagesy($source);
 
// IF NO RESIZING IS NEEDED
   if ($imageX <= $width)
   {
      return FALSE;
   }
 
// THE WIDTH IS TOO GREAT - MUST RESIZE
   $tnailX = $width;
   $tnailY = (int) (($tnailX * $imageY) / $imageX );
 
// WHICH FUNCTIONS CAN RESIZE / RESAMPLE THE IMAGE?
   if ($gdv >= 2)
   {
// IF GD IS AT LEVEL 2 OR ABOVE
      $target = imagecreatetruecolor($tnailX, $tnailY);
      imagecopyresampled ($target, $source, 0, 0, 0, 0, $tnailX, $tnailY, $imageX, $imageY);
   } else
   {
// IF GD IS AT A LOWER REVISION LEVEL
      $target = imagecreate($tnailX, $tnailY);
      imagecopyresized   ($target, $source, 0, 0, 0, 0, $tnailX, $tnailY, $imageX, $imageY);
   }
   return $target ;
}
/* ********************************************************************************************* */
 
 
// ESTABLISH THE NAME OF THE PHOTOS DIRECTORY
$photos	= 'photos';
 
// ESTABLISH THE LARGEST FILE WE WILL UPLOAD
$max_file_size = '5000000'; // A BIT MORE THAN 4MB
 
// THIS IS A LIST OF THE POSSIBLE ERRORS THAT CAN BE REPORTED in $_FILES[]["error"]
$errors	= array(
	0=>"<font color=green>Success!</font>",
	1=>"<font color=gold>The uploaded file exceeds the upload_max_filesize directive in php.ini</font>",
	2=>"<font color=gold>The uploaded file exceeds the MAX_FILE_SIZE directive that was specified in the HTML form</font>",
	3=>"<font color=gold>The uploaded file was only partially uploaded</font>",
	4=>"<font color=gold>No file was uploaded</font>",
	6=>"<font color=gold>Missing a temporary folder</font>",
	7=>"<font color=gold>Cannot write file to disk</font>"
);
 
// IF THERE IS NOTHING USEFUL IN $_POST, PUT UP THE FORM FOR INPUT
if ( (empty($_POST['p'])) && (empty($_POST['MAX_FILE_SIZE'])) ) {
	?>
	<h2>Upload Photos</h2>
 
	<!-- ENCTYPE -->
	<form name="UploadForm" enctype="multipart/form-data" action="<?=$_SERVER["REQUEST_URI"]?>" method="POST">
	<input type="hidden" name="p" value="1" />
	<!-- MAX_FILE_SIZE must precede the file input field -->
	<input type="hidden" name="MAX_FILE_SIZE" value="<?=$max_file_size?>" />
	<!-- INPUT NAME= IN TYPE=FILE DETERMINES THE NAME FOR ACTION SCRIPT TO USE IN $_FILES ARRAY -->
	<p>
	Find the photo you want to upload and click the "Upload" button below.
	</p>
 
	<table cellpadding="1" cellspacing="1" border="0">
	<tr><td align="right"><span class="required">Photo: </span></td> <td><input name="userfile" type="file" size="80" /></td></tr>
	<tr><td> </td><td><input type="submit" name="_submit" value="Upload" />
	&nbsp; &nbsp; Check this box <input autocomplete="off" type="checkbox" name="overwrite" /> to <b>overwrite</b> an existing photo.</td></tr>
	</table>
	</form>
	<?php
 
	die();
 
} else {
 
// THERE IS POST DATA - PROCESS IT
	echo "<h2>Results: Upload Photos</h2>\n";
	echo "<p>\n";
 
// SYNTHESIZE THE NEW FILE NAME
	$f_type	= trim(strtolower(end    (explode( '.', basename($_FILES['userfile']['name'] )))));
	$f_name	= trim(strtolower(current(explode( '.', basename($_FILES['userfile']['name'] )))));
	$my_new = getcwd() . '/' . $photos . '/' . $f_name .'.'. $f_type;
	$my_file= $photos . '/' . $f_name .'.'. $f_type;
 
// TEST FOR ALLOWABLE EXTENSIONS
	if ($f_type != 'jpg')
	{
	   die('Sorry, only JPG files allowed');
	}
 
// IF THERE ARE ERRORS
	$error_code	= $_FILES["userfile"]["error"];
	if ($error_code != 0)
	{
		$error_message = $errors[$error_code];
		echo "<p class=\"required\">Upload Error Code: $error_code: $error_message</p>\n";
		die('Sorry');
	}
 
// MOVE THE FILE INTO THE DIRECTORY
	$overwrite	= $_POST['overwrite'];
	$file_size	= number_format($_FILES["userfile"]["size"]);
 
// IF THE FILE IS NEW
	if (!file_exists($my_new))
	{
		if (move_uploaded_file($_FILES['userfile']['tmp_name'], $my_new))
		{
			$upload_success = 1;
		} else
		{
			$upload_success = -1;
		}
 
// IF THE FILE ALREADY EXISTS
	} else
	{
		echo "<b><i>$my_file</i></b> already exists.\n";
 
// SHOULD WE OVERWRITE THE FILE? IF NOT
		if (empty($overwrite))
		{
			$upload_success = 0;
 
// IF WE SHOULD OVERWRITE THE FILE, TRY TO MAKE A BACKUP
		} else
		{
			$now	= date('Y-m-d');
			$my_bak = $my_new . '.' . $now . '.bak';
			if (!copy($my_new, $my_bak))
			{
				echo "<b>Attempted Backup Failed!</b>\n";
			}
			if (move_uploaded_file($_FILES['userfile']['tmp_name'], $my_new))
			{
				$upload_success = 2;
			} else
			{
				$upload_success = -1;
			}
		}
	}
 
// REPORT OUR SUCCESS OR FAILURE
	if ($upload_success == 2) { echo "It has been overwritten.\n"; }
	if ($upload_success == 1) { echo "<b><i>$my_file</i></b> has been saved.\n"; }
	if ($upload_success == 0) { echo "<b>It was NOT overwritten.</b>\n"; }
 
	if ($upload_success > 0)
	{
		echo "$file_size bytes uploaded.\n";
		chmod ($my_new, 0755);
	}
 
	echo "</p>\n";
 
// RESIZE THE FILE TO FIT PAGE WIDTH, IF NECESSARY
	if ($upload_success > 0)
	{
		if ($imageblob	= create_right_size_image($my_new))
		{
			imagejpeg($imageblob, $my_new);
		}
	}
 
	echo "<p><a href=\"$my_file\">See the file</a></p>\n";
 
 
	die('Done');
}
?>

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