问在ionic和php之间使用application/x-www-form-urlencoded

EN

upload_image():Observable<any>{
    //This is not the complete string.
    let _image64 = "data:image/jpeg;base64,/9j/4AAQSkZJRgABAQAAAQABAAD/2wBDABALDA4MChAODQ4SERATGC";
    let params = `image64_str=${_image64}`;
    let headers = new HttpHeaders().set('Content-Type', 'application/x-www-form-urlencoded');
    let httpOptions = {headers};
    return this.http.post<any>("http://API_URL",params,httpOptions);
}

<?php
header("Access-Control-Allow-Origin: *");
header("Access-Control-Allow-Credentials: true");
header('Content-type: application/x-www-form-urlencoded');
$strimg = $_POST['image_str64'];
$image_str = substr($strimg ,strpos($strimg , ',')+1); //To avoid "data:image/jpeg;base64," from the 64string
$data = base64_decode($image_str);
//
//rest of code to check the format, directory and so one.
//

<b>Warning</b>:  imagecreatefromstring(): gd-jpeg: JPEG library reports unrecoverable error:  in <b>/API/test.php</b> on line <b>57</b>
<b>Warning</b>:  imagecreatefromstring(): Passed data is not in 'JPEG' format in <b>/API/test.php</b> on line <b>57</b>
<b>Warning</b>:  imagecreatefromstring(): Couldn't create GD Image Stream out of Data in <b>/API/test.php</b> on line <b>57</b>