TET Cookbook

cookbook

tet_and_pdflib/highlight_unmapped_glyphs

Use TET and PDFlib to find all glyphs for which TET could not determine a Unicode mapping, and make them visible with the "Highlight" annotation.

Download Java Code  Show Output  Show Input (service_manual.pdf) 

package com.pdflib.cookbook.tet.tet_and_pdflib;

import java.io.PrintStream;
import java.io.UnsupportedEncodingException;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;

import com.pdflib.PDFlibException;
import com.pdflib.TET;
import com.pdflib.TETException;
import com.pdflib.pdflib;

/**
 * Highlight unmapped glyphs: Find all glyphs for which TET could not determine
 * a Unicode mapping, and make them visible with the "Highlight" annotation.
 * Note that the counts of unmappable glyphs may include blanks, as blanks may
 * be undistinguishable from other glyphs for which no Unicode mapping is
 * available.
 * <p>
 * Required software: TET 3 and PDFlib+PDI 8
 * <p>
 * Required data: PDF document
 * 
 */
class highlight_unmapped_glyphs {
    /**
     * Common search path for PDI and TET to find the input document.
     */
    private static final String DOC_SEARCH_PATH = "../input";

    /**
     * Global option list. The program expects the "resource" directory parallel to
     * the "java" directory.
     */
    private static final String GLOBAL_OPTLIST = "searchpath={../resource/cmap ../resource/glyphlist " + DOC_SEARCH_PATH
            + "}";

    /**
     * Document specific option list.
     */
    private static final String DOC_OPTLIST = "";

    /**
     * Page-specific option list.
     */
    private static final String PAGE_OPTLIST = "granularity=page";

    /**
     * The encoding in which the output is sent to System.out. For running the
     * example in a Windows command window, you can set this for example to
     * "windows-1252" for getting Latin-1 output.
     */
    private static final String OUTPUT_ENCODING = System.getProperty("file.encoding");

    /**
     * For printing to System.out in the encoding specified via OUTPUT_ENCODING.
     */
    private static PrintStream out;

    /**
     * The name of the input file
     */
    private String infilename;

    /**
     * The name of the output file
     */
    private String outfilename;

    /**
     * Nudge factor for ascender height of the annotations (relative to the font
     * size)
     */
    private static final double ASCENDER = 0.85;

    /**
     * Nudge factor for descender height of annotations (relative to the font size)
     */
    private static final double DESCENDER = 0.25;

    /**
     * Counter for unmapped glyphs in document.
     */
    private int unmappedGlyphs = 0;

    /**
     * Import the current page from the PDI import document and place it in the
     * ouput document.
     *
     * @param p         the pdflib object
     * @param pdiHandle the PDI handle for the input document
     * @param pageno    the current page number
     *
     * @throws PDFlibException an error occurred in the PDFlib API
     */
    private boolean importPdiPage(pdflib p, int pdiHandle, int pageno) throws PDFlibException {
        /*
         * The page size will be adjusted later to match the size of the input pages
         */
        p.begin_page_ext(10, 10, "");
        int pdiPage = p.open_pdi_page(pdiHandle, pageno, "");

        if (pdiPage == -1) {
            System.err.println("Error: " + p.get_errmsg());
            return false;
        }

        /* Place the input page and adjust the page size */
        p.fit_pdi_page(pdiPage, 0, 0, "adjustpage");
        p.close_pdi_page(pdiPage);

        return true;
    }

    /**
     * Helper class to store rectangle data.
     */
    private class rectangle {
        rectangle(int unmappedGlyphs, double llx, double lly, double urx, double ury) {
            this.llx = llx;
            this.lly = lly;
            this.urx = urx;
            this.ury = ury;
            this.unmappedGlyphs = unmappedGlyphs;
        }

        double llx;
        double lly;
        double urx;
        double ury;

        int unmappedGlyphs = 0;
    }

    /**
     * Get the font name for the pCOS id of a font
     * 
     * @param tet    The TET object
     * @param doc    The TET document handle
     * @param pcosId The pCOS id of the font to check
     * @return The name of the font
     * @throws TETException An error occurred in the TET API
     */
    private String getFontName(TET tet, int doc, int pcosId) throws TETException {
        String fontName = tet.pcos_get_string(doc, "fonts[" + pcosId + "]/name");
        return fontName;
    }

    /**
     * Create annotations for a given list of rectangles.
     * 
     * @param tet        The TET object
     * @param doc        The TET handle
     * @param p          The pdflib object
     * @param rectangles The list of rectangles
     * @throws TETException    An error occurred in the TET API
     * @throws PDFlibException An error occurred in the PDFlib API
     */
    private void create_annotations(TET tet, final int doc, pdflib p, List<rectangle> rectangles, int fontId)
            throws TETException, PDFlibException {

        StringBuffer optlist = new StringBuffer("annotcolor {rgb 0.68 0.85 0.90} linewidth 1 ")
                .append("title {TET/PDFlib Unmapped Glyph Highlighting} ").append("polylinelist {");

        /*
         * Build the option list for the highlight annotation, including the
         * "polylinelist" option that describes one or multiple rectangles for the
         * highlighting annotation for the potentially hyphenated word.
         *
         * We still need the rectangle that surrounds the separate sub-rectangles of the
         * annotation, for passing it to the function create_annotation(). To get the
         * actual values, we start with impossible values and compute the minimum and
         * maximum accross the relevant values.
         */
        double minx = 1E10, miny = 1E10, maxx = -1, maxy = -1;

        Iterator<rectangle> i = rectangles.iterator();
        int unmappedGlyphCount = 0;
        while (i.hasNext()) {
            /*
             * The quadrilaterals have to be built in the following order: upper left corner
             * -> upper right corner -> lower left corner -> lower right corner
             */
            rectangle r = (rectangle) i.next();

            unmappedGlyphCount += r.unmappedGlyphs;
            minx = Math.min(minx, r.llx);
            miny = Math.min(miny, r.lly);
            maxx = Math.max(maxx, r.urx);
            maxy = Math.max(maxy, r.ury);

            optlist.append("{");

            // upper left corner
            optlist.append(r.llx).append(" ").append(r.ury);
            // upper right corner
            optlist.append(" ").append(r.urx).append(" ").append(r.ury);
            // lower left corner
            optlist.append(" ").append(r.llx).append(" ").append(r.lly);
            // lower right corner
            optlist.append(" ").append(r.urx).append(" ").append(r.lly);

            optlist.append("} ");
        }
        optlist.append("} contents {Font: \"").append(getFontName(tet, doc, fontId)).append("\" Glyphs: ")
                .append(unmappedGlyphCount).append("} ");

        p.create_annotation(minx, miny, maxx, maxy, "Highlight", optlist.toString());

        /*
         * accumulate total count
         */
        unmappedGlyphs += unmappedGlyphCount;
    }

    /**
     * Process a page: Create a new page in the output document, place the page from
     * the input document in the output document, and create "Highlight" annotations
     * for all sequences of unmapped glyphs.
     * <p>
     * The code assumes that all glyphs of a sequence of unmapped glyphs have the
     * same font. It also ignores any angle of the text.
     * 
     * @param tet       TET object
     * @param doc       TET document handle
     * @param p         pdflib object
     * @param pdiHandle PDI document handle
     * @param pageno    The current page number
     * @throws TETException    An error occurred in the TET API
     * @throws PDFlibException An error occurred in the PDFlib API
     */
    private void process_page(TET tet, final int doc, pdflib p, int pdiHandle, int pageno)
            throws TETException, PDFlibException {
        /*
         * Copy page from input document to output document.
         */
        importPdiPage(p, pdiHandle, pageno);

        final int page = tet.open_page(doc, pageno, PAGE_OPTLIST);

        if (page == -1) {
            System.err.println("Error " + tet.get_errnum() + " in " + tet.get_apiname() + "(): " + tet.get_errmsg());
        } else {
            /* Retrieve all text fragments for the page */
            for (String text = tet.get_text(page); text != null; text = tet.get_text(page)) {
                /*
                 * List for collecting the rectangles that belong to an instance of the search
                 * term
                 */
                List<rectangle> rectangles = new LinkedList<rectangle>();

                double llx = 0, lly = 0, urx = 0, ury = 0, lasty = 0;
                int fontId = -1;

                /*
                 * Loop over all characters, watch the y position for a jump and the font id for
                 * a change to detect word fragments that have the same font. Recangles from
                 * multiple lines that have the same font belong to a common annotation.
                 */
                boolean inHighlightSequence = false;
                int unmappedGlyphs = 0;
                while (tet.get_char_info(page) != -1) {
                    // ignore inserted separators
                    if (tet.type == 12) {
                        continue;
                    }

                    boolean jumped = lasty != tet.y;
                    boolean fontChange = fontId != tet.fontid;

                    if (jumped || fontChange || !tet.unknown) {
                        if (inHighlightSequence) {
                            /*
                             * y value jumped, font changed or glyph is no longer unmapped, so we have to
                             * start a new rectangle
                             */
                            rectangles.add(new rectangle(unmappedGlyphs, llx, lly, urx, ury));
                            unmappedGlyphs = 0;

                            /*
                             * If the font changed or the glyph is no longer unmapped, the current
                             * annotation is complete.
                             */
                            if (fontChange || !tet.unknown) {
                                create_annotations(tet, doc, p, rectangles, fontId);
                                rectangles = new LinkedList<rectangle>();
                            }
                        }

                        /*
                         * Remember new lower left corner of potential next rectangle.
                         */
                        llx = tet.x;
                        lasty = tet.y;
                        lly = tet.y - DESCENDER * tet.fontsize;
                    }

                    inHighlightSequence = tet.unknown;

                    /*
                     * Count the glyph if we are in a highlight sequence and if it is not an
                     * "artificial" character (see TET Manual for description of the TET "type"
                     * member.
                     */
                    if (inHighlightSequence && (tet.type == 0 || tet.type == 1)) {
                        unmappedGlyphs += 1;
                    }

                    fontId = tet.fontid;
                    urx = tet.x + tet.width;
                    ury = tet.y + ASCENDER * tet.fontsize;
                }

                /*
                 * Add the last identified rectangle.
                 */
                if (inHighlightSequence) {
                    rectangles.add(new rectangle(unmappedGlyphs, llx, lly, urx, ury));
                    create_annotations(tet, doc, p, rectangles, fontId);
                }
            }

            if (tet.get_errnum() != 0) {
                System.err
                        .println("Error " + tet.get_errnum() + " in " + tet.get_apiname() + "(): " + tet.get_errmsg());
            }

            /*
             * Close page in the input and output documents.
             */
            p.end_page_ext("");
            tet.close_page(page);
        }
    }

    private void execute() {
        TET tet = null;
        pdflib p = null;
        int pageno = 0;

        try {
            tet = new TET();
            tet.set_option(GLOBAL_OPTLIST);

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

            if (p.begin_document(outfilename, "") == -1) {
                System.err.println("Error: " + p.get_errmsg());
                return;
            }

            /* add document info entries */
            p.set_info("Creator", "Highlight Unmapped Glyphs TET Cookbook Example");
            p.set_info("Author", "PDFlib GmbH");
            p.set_info("Title", infilename);

            int pdiHandle = p.open_pdi_document(infilename, "");
            if (pdiHandle == -1) {
                System.err.println("Error: " + p.get_errmsg());
                return;
            }

            final int doc = tet.open_document(infilename, DOC_OPTLIST);
            if (doc == -1) {
                System.err
                        .println("Error " + tet.get_errnum() + " in " + tet.get_apiname() + "(): " + tet.get_errmsg());
                return;
            }

            /*
             * Loop over pages in the document
             */
            final int n_pages = (int) tet.pcos_get_number(doc, "length:pages");
            for (pageno = 1; pageno <= n_pages; ++pageno) {
                process_page(tet, doc, p, pdiHandle, pageno);
            }

            out.println("Created PDF output document \"" + outfilename + "\" with " + unmappedGlyphs
                    + " unmapped glyphs highlighted.");
            p.end_document("");
            p.close_pdi_document(pdiHandle);
            tet.close_document(doc);
        } catch (TETException e) {
            if (pageno == 0) {
                System.err
                        .println("Error " + e.get_errnum() + " in " + e.get_apiname() + "(): " + e.get_errmsg() + "\n");
            } else {
                System.err.println("Error " + e.get_errnum() + " in " + e.get_apiname() + "() on page " + pageno + ": "
                        + e.get_errmsg() + "\n");
            }
        } catch (PDFlibException e) {
            if (pageno == 0) {
                System.err
                        .println("Error " + e.get_errnum() + " in " + e.get_apiname() + "(): " + e.get_errmsg() + "\n");
            } else {
                System.err.println("Error " + e.get_errnum() + " in " + e.get_apiname() + "() on page " + pageno + ": "
                        + e.get_errmsg() + "\n");
            }
        } finally {
            tet.delete();
            p.delete();
        }
    }

    /**
     * @param infilename  the name of the file for which the file with highlighted
     *                    unmapped glyphs will be generated
     * @param outfilename the name of the output file
     */
    private highlight_unmapped_glyphs(String infilename, String outfilename) {
        this.infilename = infilename;
        this.outfilename = outfilename;
    }

    public static void main(String[] args) throws UnsupportedEncodingException {
        System.out.println("Using output encoding \"" + OUTPUT_ENCODING + "\"");
        out = new PrintStream(System.out, true, OUTPUT_ENCODING);

        if (args.length != 2) {
            out.println("usage: highlight_unmapped_glyphs <infilename> <outfilename>");
            return;
        }

        highlight_unmapped_glyphs t = new highlight_unmapped_glyphs(args[0], args[1]);
        t.execute();
    }
}