ALTO XML structure

<?xml version="1.0"?>
<alto>
  <Description>
    <MeasurementUnit/>
    <sourceImageInformation/>
    <Processing/>
  </Description>
  <Styles>
    <TextStyle/>
    <ParagraphStyle/>
  </Styles>
  <Layout>
    <Page>
      <TopMargin/>
      <LeftMargin/>
      <RightMargin/>
      <BottomMargin/>
      <PrintSpace/>
    </Page>
  </Layout>
</alto>