jquery(Jcrop)+PHP cuts pictures according to coordinates

/*** Goofy 2011-11-29 * Image processing: According to the passed coordinate parameters, x, y, w, h, are the selected x coordinate, y coordinate, w width, and h height in turn. * Copy this area to the blank image created in the first step through the imagecopy() method * Note that when creating an image, you must use imagecreatetruecolor() for true color, otherwise the image will be distorted using imagecreate()*/

/**
 * Goofy 2011-11-29
 * Image processing: According to the passed coordinate parameters, x, y, w, h, are the selected x coordinate, y coordinate, w width, h height in turn
 * Through the imagecopy() method Copy this area to the blank image created in the first step
 * Note that when creating the image, you must use imagecreatetruecolor() for true color, otherwise the image will be distorted using imagecreate()
*/


//The proportion passed from the page
$scale=$_GET['scale'];
//The following attributes are multiplied by the corresponding Scale
$x=$_GET['x']*$scale;
$y=$_GET['y']*$scale;
$w=$_GET['w']*$scale;
$h= $_GET['h']*$scale;

//Source path
$src=$_GET['src'];

//Do you want to continue? If you do not continue to take screenshots of this picture, the source picture will be deleted
$again="off";
if(!empty($_GET['again'])){
 $again=$_GET['again'];
}

//The first step is to create an image based on the passed width and height parameters, and then fill the intercepted part into this area
header("Content-type: image/jpeg");
 $target = @imagecreatetruecolor($w,$h)
 or die("Cannot Initialize new GD image stream");

//The second step is to get the source image according to the path and create an image object using the source image
$ source = imagecreatefromjpeg($src);

//The third step, according to the passed parameters, select a part of the source image to fill in the image created in the first step
imagecopy( $target, $source, 0, 0, $ x, $y, $w, $h);

//The fourth step, save the image
 //Intercept and organize the new path
$pos_path= strripos($src, "/");
$newPath=substr( $src,0,$pos_path-strlen($src))."_new/";
 //Intercept and organize new names
$pos_name=strripos($src, ".");
$newName=substr($src ,0,$pos_name);
$pos_name_= strripos($newName, "/");
 //The suffix ".jpg" is not added here temporarily to prevent duplicate files. If there are, they need to be renamed and added. It will be inconvenient
$newName=substr($newName,$pos_name_-strlen($newName)+1)."_";
 //Generate pictures without suffix
$file=$newPath.$newName;

/ /Append asc code to rename the file. You can also name it with random numbers, time, etc. I don’t need those naming methods for project requirements
for($i=0;$i<26;$i++){

 //If the directory exists
 if(is_dir($newPath)){
 //If the file exists, continue looping until there are no files with the same name
 if(is_file($file.chr(97+$i).".jpg")){
 continue;
 }else{
 //Create file
 imagejpeg($target,$file.chr(97+$i).".jpg",100);
 //After file creation is completed, determine whether to delete the source file, off is Delete the source file
 if($again=="off"){
 unlink($src);
 unset($_SESSION['url']);
 }
 break;

 }
 }else{
 //Create Directory
 mkdir($newPath);
 //Create file
 imagejpeg($target,$file.chr(97+$i).".jpg",100);
 //After file creation is completed, determine whether to delete the source file, off is to delete the source file
 if($again=="off"){
 unlink($src);
 unset($_SESSION['url']);
 }
 break;
 }
}
//Jump Go to the homepage
Header("Location: index.php");
?>