import java.io.FileOutputStream;
import com.lowagie.text.Document;
import com.lowagie.text.PageSize;
import com.lowagie.text.pdf.PdfContentByte;
import com.lowagie.text.pdf.PdfImportedPage;
import com.lowagie.text.pdf.PdfReader;
import com.lowagie.text.pdf.PdfWriter;
public class MainClass {
public static void main(String[] args) throws Exception {
Document document = new Document(PageSize.A4);
PdfReader reader = new PdfReader("1.pdf");
PdfWriter writer = PdfWriter.getInstance(document, new FileOutputStream("my.pdf"));
document.open();
PdfContentByte cb = writer.getDirectContent();
PdfImportedPage page = writer.getImportedPage(reader, 1);
cb.addTemplate(page, -0.5f, 0f, 0f, -0.5f, PageSize.A4.width() / 2, PageSize.A4.height());
document.close();
}
}