无法在PHP服务器上上传和保存大图像文件

I have written the php upload image files to php server. When small images within 100kB, it is success. But when over 500KB, it is failed and said no data received on server. I also do not know why. No file saved in php server of this uploading. Do you know how to solve??

function uploadImages($input, $file)
{

    if($input == null || $input == "")
    {
        return false;
    }
    $stringVal = $input; 
    $value  = str_replace('data:image/png;base64,', '', $stringVal);

    if ($this->check_base64_image($value) == false) {
        return false;
    }

    $actualFile  = base64_decode($value);
    $img = imagecreatefromstring($actualFile);
    $imgSize = getimagesize('data://application/octet-stream;base64,' . base64_encode($actualFile));


    if ($img == false) {
        return false;
    }else
    {

        /*** maximum filesize allowed in bytes ***/
        $max_file_length  = 100000;

        log_message('debug', 'PRE UPLOADING!!!!!!!!');

        if (isset($img)){

            log_message('debug', 'UPLOADING!!!!!!!!');

            // check the file is less than the maximum file size
            if($imgSize['0'] > $max_file_length || $imgSize['1'] > $max_file_length)
            {
                log_message('debug', 'size!!!!!!!!'.print_r($imgSize));
                $messages = "File size exceeds $max_file_size limit";
                return false;
            }else if (file_exists($file)) {
                return false;
            }else
            {
                file_put_contents($file, $actualFile);
                return true;
            }
        }       
    } 
}

try this,

ini_set('post_max_size',52428800); // 50 MB
ini_set('upload_max_filesize',52428800) // 50 MB