$attachmentId = media_handle_upload('image', 0);

$img= get_attached_file($attachmentId);

function crop($filePath, $cropWidth, $cropHeight, $cropX, $cropY){

    // returns imageCreateFromJpeg($filepath),
    $image = $this->createImageFromAnyType($filepath);

    $cropped = imagecrop($image, ['x' => $cropX,
                       'y' => $cropY, 'width' => $cropWidth, 'height' => $cropHeight]);

    return $cropped ? imagejpeg($cropped) : false;
}