Image Upload using the gd library and PHP

require_once('Connections/connBookShop.php');
 
if (!function_exists("GetSQLValueString")) {
function GetSQLValueString($theValue, $theType, $theDefinedValue = "", $theNotDefinedValue = "") 
{
  $theValue = get_magic_quotes_gpc() ? stripslashes($theValue) : $theValue;
 
  $theValue = function_exists("mysql_real_escape_string") ? mysql_real_escape_string($theValue) : mysql_escape_string($theValue);
 
  switch ($theType) {
    case "text":
      $theValue = ($theValue != "") ? "'" . $theValue . "'" : "NULL";
      break;    
    case "long":
    case "int":
      $theValue = ($theValue != "") ? intval($theValue) : "NULL";
      break;
    case "double":
      $theValue = ($theValue != "") ? "'" . doubleval($theValue) . "'" : "NULL";
      break;
    case "date":
      $theValue = ($theValue != "") ? "'" . $theValue . "'" : "NULL";
      break;
    case "defined":
      $theValue = ($theValue != "") ? $theDefinedValue : $theNotDefinedValue;
      break;
  }
  return $theValue;
}
}
 
// Maximum file size
define ("max_size","500");
 
// Large image size
define ("width","245");
define ("height","300");
 
// Thumnail image size
define ("width_tn","96");
define ("height_tn","96");
 
// this is the function that will create the thumbnail image from the uploaded image
// the resize will be done considering the width and height defined, but without deforming the image
function make_thumb($img_name,$filename,$new_w,$new_h)
{
	//get image extension.
		$ext=getExtension($img_name);
	//creates the new image using the appropriate function from gd library
		if(!strcmp("jpg",$ext) || !strcmp("jpeg",$ext))
			$src_img=imagecreatefromjpeg($img_name);
		if(!strcmp("png",$ext))
			$src_img=imagecreatefrompng($img_name);
	//gets the dimmensions
			$old_x=imageSX($src_img);
			$old_y=imageSY($src_img);
	// next we will calculate the new dimmensions for the thumbnail image
			$ratio1=$old_x/$new_w;
			$ratio2=$old_y/$new_h;
		if($ratio1>$ratio2) {
			$thumb_w=$new_w;
			$thumb_h=$old_y/$ratio1;
		}
		else {
			$thumb_h=$new_h;
			$thumb_w=$old_x/$ratio2;
}
// we create a new image with the new dimmensions
$dst_img=ImageCreateTrueColor($thumb_w,$thumb_h);
// resize the big image to the new created one
imagecopyresampled($dst_img,$src_img,0,0,0,0,$thumb_w,$thumb_h,$old_x,$old_y);
// output the created image to the file. Now we will have the thumbnail into the file named by $filename
if(!strcmp("png",$ext))
imagepng($dst_img,$filename);
else
imagejpeg($dst_img,$filename);
//destroys source and destination images.
imagedestroy($dst_img);
imagedestroy($src_img);
}
// This function reads the extension of the file.
// It is used to determine if the file is an image by checking the extension.
function getExtension($str) {
$i = strrpos($str,".");
if (!$i) { return ""; }
$l = strlen($str) - $i;
$ext = substr($str,$i+1,$l);
return $ext;
}
 
 
//Here follows the php code to process post data.
//The code contains image extension and size verification as well as uploading and resizing image.
// This variable is used as a flag. The value is initialized with 0 (meaning no error found)
//and it will be changed to 1 if an error occures. If the error occures the file will not be uploaded.
$errors=0;
 
// checks if the form has been submitted
if(isset($_POST['Submit']))
{
//reads the name of the file the user submitted for uploading
$image=$_FILES['image']['name'];
// if it is not empty
if ($image)
{
// get the original name of the file from the clients machine
$filename = stripslashes($_FILES['image']['name']);
// get the extension of the file in a lower case format
$extension = getExtension($filename);
$extension = strtolower($extension);
// if it is not a known extension, we will suppose it is an error, print an error message
//and will not upload the file, otherwise we continue
if (($extension != "jpg") && ($extension != "jpeg") && ($extension != "png"))
{
echo '<h1>Unknown extension!</h1>';
$errors=1;
}
else
{
// get the size of the image in bytes
// $_FILES[\'image\'][\'tmp_name\'] is the temporary filename of the file in which
//the uploaded file was stored on the server
$size=getimagesize($_FILES['image']['tmp_name']);
$sizekb=filesize($_FILES['image']['tmp_name']);
//compare the size with the maxim size we defined and print error if bigger
if ($sizekb > max_size*1024)
{
echo '<h1>You have exceeded the size limit!</h1>';
$errors=1;
}
//we will give an unique name, for example the time in unix time format
$image_name=time().'.'.$extension;
//the new name will be containing the full path where will be stored (images folder)
$newname="assets/images/book_cover/large/".$image_name;
$copied = copy($_FILES['image']['tmp_name'], $newname);
//we verify if the image has been uploaded, and print error instead
if (!$copied)
{
echo '<h1>Copy unsuccessfull!</h1>';
$errors=1;
}
else
{
// the new thumbnail image will be placed in images/thumbs/ folder
$thumb_name='assets/images/book_cover/'.$image_name;
// call the function that will create the thumbnail. The function will get as parameters
//the image name, the thumbnail name and the width and height desired for the thumbnail
$thumb=make_thumb($newname,$thumb_name,width_tn,height_tn);
}} }}
//If no errors registred, print the success message and show the thumbnail image created
if(isset($_POST['Submit']) && !$errors)
{
echo "<h1>Thumbnail created Successfully!</h1>";
echo '<img src="'.$thumb_name.'">';
}
 
 
// Insert into database
$editFormAction = $_SERVER['PHP_SELF'];
if (isset($_SERVER['QUERY_STRING'])) {
  $editFormAction .= "?" . htmlentities($_SERVER['QUERY_STRING']);
}
 
if ((isset($_POST["MM_insert"])) && ($_POST["MM_insert"] == "uploadForm")) {
 $insertSQL = sprintf("INSERT INTO items (ItemName, ItemLongDesc, ItemPrice, ItemThumb, ItemImage, ItemQnty) VALUES (%s, %s, %s, %s, %s, %s)",
                     GetSQLValueString($_POST['itemName'], "text"),
                     GetSQLValueString($_POST['itemDesc'], "text"),
                     GetSQLValueString($_POST['itemPrice'], "double"),
                     GetSQLValueString($image_name, "text"),
                     GetSQLValueString($image_name, "text"),
                     GetSQLValueString($_POST['itemQnty'], "int"));
 
  mysql_select_db($database_connBookShop, $connBookShop);
  $Result1 = mysql_query($insertSQL, $connBookShop) or die(mysql_error());
}