$handle = new \verot\Upload\Upload($_FILES['image_field']);
if ($handle->uploaded) {
$handle->file_new_name_body = 'image_resized';
$handle->image_resize = true;
$handle->image_x = 100;
$handle->image_ratio_y = true;
$handle->process('/home/user/files/');
if ($handle->processed) {
echo 'image resized';
$handle->clean();
} else {
echo 'error : ' . $handle->error;
}
}