PDFlib Cookbook

cookbook

pdf_import/crop_imported_pages

Crop the pages of an existing PDF document.

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/*
 * Crop imported pages:
 * Crop pages of an existing PDF document
 *
 * Import a PDF page and reduce the page by some fixed amount before placing
 * it in the output document. The retrieve the dimensions of the imported page
 * and place it on a page size of 1/4 of the original size.
 *
 * Required software: PDFlib+PDI/PPS 9
 * Required data: PDF document
 */
package com.pdflib.cookbook.pdflib.pdf_import;

import com.pdflib.pdflib;
import com.pdflib.PDFlibException;

public class crop_imported_pages
{
    public static void main (String argv[])
    {
        /* This is where the data files are. Adjust as necessary. */
        String searchpath = "../input";

        /* By default annotations are also imported. In some cases this
         * requires the Noto fonts for creating annotation appearance streams.
         * We therefore set the searchpath to also point to the font directory.
         */
        String fontpath = "../resource/font";
        String outfile = "crop_imported_pages.pdf";
        String title = "Crop Imported Pages";

        pdflib p = null;
        String pdffile = "kraxi_business_cards.pdf";
        int indoc, pageno, endpage, page;
        int exitcode = 0;

        try {
            p = new pdflib();

            p.set_option("searchpath={" + searchpath + "}");

            p.set_option("searchpath={" + fontpath + "}");

            /* This means we must check return values of load_font() etc. */
            p.set_option("errorpolicy=return");

            if (p.begin_document(outfile, "") == -1)
                throw new Exception("Error: " + p.get_errmsg());

            p.set_info("Creator", "PDFlib Cookbook");
            p.set_info("Title", title);

            /* Open the input PDF */
            indoc = p.open_pdi_document(pdffile, "");
            if (indoc == -1)
                throw new Exception("Error: " + p.get_errmsg());

            endpage = (int) p.pcos_get_number(indoc, "length:pages");

            /* Loop over all pages of the input document */
            for (pageno = 1; pageno <= endpage; pageno++)
            {
                page = p.open_pdi_page(indoc, pageno, "");

                if (page == -1)
                    throw new Exception("Error: " + p.get_errmsg());

                /* Page size may be adjusted by fit_pdi_page().*/
                p.begin_page_ext(0, 0, "width=a4.width height=a4.height");

                /* Place the imported page without performing
                 * any changes on the output page
                 */
                p.fit_pdi_page(page, 0, 0, "adjustpage");

                p.end_page_ext("");

                /* Page size may be adjusted by fit_pdi_page().*/
                p.begin_page_ext(0, 0, "width=a4.width height=a4.height");

                /* Place the imported page, adjust the page size
                 * to the size of the imported page, and crop the page by 51.
                 */
                p.fit_pdi_page(page, -51, -51, "adjustpage");
                
                p.end_page_ext("");
                
                /* Retrieve the dimensions of the imported page and adjust the page
                 * size by cropping it to a certain percentage of the imported page
                 * size.
                 */
                
                /* Retrieve the width and height of the current page (note that
                 * indices for the pages pseudo object start at 0):
                 */
                double pagewidth = 
                    p.pcos_get_number(indoc, "pages[" + (pageno - 1) + "]/width");
                double pageheight = 
                    p.pcos_get_number(indoc, "pages[" + (pageno - 1) + "]/height");
                
                /* Set the new page size to 1/4 of the imported page size */
                p.begin_page_ext(pagewidth/4, pageheight/4, "");
                
                /* Place the imported page and scale it to 1/4 of its page size */
                p.fit_pdi_page(page, 0, 0, "boxsize={" + pagewidth/4 + " " +
                    pageheight/4 + "} fitmethod=meet");
                
                p.end_page_ext("");
                
                p.close_pdi_page(page);
            }

            p.end_document("");

        } catch (PDFlibException e) {
            System.err.println("PDFlib exception occurred:");
            System.err.println("[" + e.get_errnum() + "] " + e.get_apiname()
                + ": " + e.get_errmsg());
            exitcode = 1;
        } catch (Exception e) {
            System.err.println(e);
            exitcode = 1;
        } finally {
            if (p != null) {
                p.delete();
            }
            System.exit(exitcode);
        }
    }
}