/* $Id: transparent_stamp_for_pdfa.java,v 1.5 2011/08/01 14:44:29 stm Exp $ * Transparent stamp for PDF/A: * Apply a transparent stamp to an existing PDF/A document while maintaining * PDF/A conformance. * * Import all pages from an existing PDF/A document and place a stamp on the * page. The stamp is filled with a pattern color, where the pattern consists of * a bitmap. The bitmap is used as a mask to create a certain percentage of * transparency. This is required since real transparency is not allowed in * PDF/A. Transparency by pattern color is PDF/A compatible, so we use it to * apply a transparent stamp on a PDF/A document while maintaining PDF/A * conformance. * * Required software: PDFlib+PDI/PPS 7 * Required data: PDF document */ package com.pdflib.cookbook.pdflib.pdfa; import com.pdflib.pdflib; import com.pdflib.PDFlibException; public class transparent_stamp_for_pdfa { public static void main (String argv[]) { /* This is where the data files are. Adjust as necessary. */ String searchpath = "../input"; String outfile = "transparent_stamp_for_pdfa.pdf"; String title = "Transparent Stamp for PDF/A"; pdflib p = null; String pdffile = "PLOP-datasheet-PDFA-1b.pdf"; int indoc, pageno, endpage, page, font, pattern; double w; double ret; String res; int image; /* data set for our halftoning bitmap */ int data[][] = { { 0x00, 0x00, /* 30% */ 0x00, 0x00, 0x00, 0x00, 0x03, 0xC0, 0x07, 0xE0, 0x0F, 0xF0, 0x1F, 0xF8, 0x1F, 0xF8, 0x1F, 0xF8, 0x1F, 0xF8, 0x0F, 0xF0, 0x07, 0xE0, 0x03, 0xC0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, }, { 0x00, 0x00, /* 20% */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x03, 0xC0, 0x07, 0xE0, 0x0F, 0xF0, 0x0F, 0xF0, 0x0F, 0xF0, 0x0F, 0xF0, 0x07, 0xE0, 0x03, 0xC0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, }}; int ht = 1; /* index in halftone array */ try { p = new pdflib(); p.set_parameter("SearchPath", searchpath); /* This means we must check return values of load_font() etc. */ p.set_parameter("errorpolicy", "return"); check_pdflib_version(p, 7, 0, 4); if (p.begin_document(outfile, "pdfa=PDF/A-1b:2005") == -1) throw new Exception("Error: " + p.get_errmsg()); p.set_info("Creator", "PDFlib Cookbook"); p.set_info("Title", title + " $Revision: 1.5 $"); /* * Open the input PDF. This must be done before creating the pattern * because the output intent must be set before defining the * pattern. */ 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"); /* * Since the input document contains its own output intent retrieve * the output intent from the input document and copy it to the * output document. */ res = p.pcos_get_string(indoc, "type:/Root/OutputIntents"); if (res.equals("array")) { ret = p.process_pdi(indoc, -1, "action=copyoutputintent"); if (ret == -1) throw new Exception("Error: " + p.get_errmsg()); } /* * Define a bitmap pattern based on an image mask. We scale down * the image to provide a smoother appearance on screen. */ byte[] bitmap = new byte[data[ht].length]; for (int j = 0; j < data[ht].length; j++) bitmap[j] = (byte) data[ht][j]; p.create_pvf("/pvf/image/bitmap", bitmap, ""); image = p.load_image("raw", "/pvf/image/bitmap", "bpc=1 components=1 height=16 width=16 invert mask"); if (image == -1) throw new Exception("Error: " + p.get_errmsg()); w = (double) 16 / 32; pattern = p.begin_pattern(w, w, w, w, 1); p.fit_image(image, 0, 0, "scale=" + (double) 1 / 32); p.end_pattern(); p.close_image(image); /* 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()); /* Dummy page size; will be adjusted later */ p.begin_page_ext(10, 10, ""); /* * Place the imported page on the output page, and adjust the * page size. */ p.fit_pdi_page(page, 0, 0, "adjustpage"); /* * Load the font for the stamp. */ font = p.load_font("DejaVuSerif", "unicode", "embedding"); if (font == -1) throw new Exception("Error: " + p.get_errmsg()); /* Place the stamp, filled with the pattern color */ p.setcolor("fill", "pattern", pattern, 0, 0, 0); p.fit_textline("PUBLISHED", 20, 20, "font=" + font + " fontsize=1 boxsize={550 800} stamp=ll2ur"); p.close_pdi_page(page); p.end_page_ext(""); } p.end_document(""); } catch (PDFlibException e) { System.err.print("PDFlib exception occurred:\n"); System.err.print("[" + e.get_errnum() + "] " + e.get_apiname() + ": " + e.get_errmsg() + "\n"); } catch (Exception e) { System.err.println(e.getMessage()); } finally { if (p != null) { p.delete(); } } } /** * Check whether the required minimum PDFlib version is available * * @param p * the pdflib object * @param major * PDFlib major version number * @param minor * PDFlib minor version number * @param revision * PDFlib revision number * * @throws PDFlibException * @throws Exception */ private static void check_pdflib_version(pdflib p, int major, int minor, int revision) throws PDFlibException, Exception { final int actualMajor = (int) p.get_value("major", 0); final int actualMinor = (int) p.get_value("minor", 0); final int actualRevision = (int) p.get_value("revision", 0); /* Required minimum PDFlib version */ final int requiredVersion = major * 100 + minor * 10 + revision; final int actualVersion = actualMajor * 100 + actualMinor * 10 + actualRevision; if (actualVersion < requiredVersion) { throw new Exception("Error: PDFlib " + major + "." + minor + "." + revision + " or above is required"); } } }