private boolean shouldBeRemoved(
BxLine line,
Population heightPopulation,
Population fontPopulation,
Population distancePopulation,
Population indentationPopulation) {
if (line.getMostPopularFontName() == null) {
return true;
}
if (heightPopulation.getZScore(line.getHeight()) < candMinHeightZScore) {
return true;
}
if (looksLikeEquation(line)) {
return true;
}
if (looksLikeFigure(line)) {
return true;
}
if (looksLikeTable(line)) {
return true;
}
if (!containsMostlyLetters(line)) {
return true;
}
if (!containsWord(line)) {
return true;
}
if (startsWithLargeNumber(line)) {
return true;
}
if (heightPopulation.getZScore(line.getHeight()) < outlHeightZScore
&& Math.abs(fontPopulation.getZScore(getFontIndex(line))) < outlFontZScore
&& (!line.hasPrev()
|| distancePopulation.getZScore(line.getY() - line.getPrev().getY())
< outlDistanceZScore)
&& Math.abs(indentationPopulation.getZScore(line.getX())) < outlIndentZScore) {
return true;
}
int i = 0;
BxLine actLine = line;
while (actLine.hasNext()) {
actLine = actLine.getNext();
if (actLine.toText().matches("[A-Z].*")) {
break;
}
if (i++ == maxHeaderLineCount) {
return true;
}
}
return false;
}
@Override
public BxContentStructure extractHeaders(BxDocument document) throws AnalysisException {
Population heightPopulation = new Population();
Population fontPopulation = new Population();
Population distancePopulation = new Population();
Population lengthPopulation = new Population();
Population indentationPopulation = new Population();
Set<BxLine> candidates = new HashSet<BxLine>();
for (BxPage page : document) {
for (BxZone zone : page) {
if (zone.getLabel().equals(BxZoneLabel.BODY_CONTENT)
|| zone.getLabel().equals(BxZoneLabel.GEN_BODY)) {
for (BxLine line : zone) {
heightPopulation.addObservation(line.getHeight());
lengthPopulation.addObservation(line.getWidth());
indentationPopulation.addObservation(line.getX());
if (line.hasPrev() && line.getY() - line.getPrev().getY() > 0) {
distancePopulation.addObservation(line.getY() - line.getPrev().getY());
}
fontPopulation.addObservation(getFontIndex(line));
if (isFirstInZone(line) && looksLikeHeader(line)) {
candidates.add(line);
}
}
}
}
}
Set<BxLine> toDelete = new HashSet<BxLine>();
for (BxLine line : candidates) {
if (shouldBeRemoved(
line, heightPopulation, fontPopulation, distancePopulation, indentationPopulation)) {
toDelete.add(line);
}
if (lengthPopulation.getZScore(line.getWidth()) > candMaxLengthZScore) {
toDelete.add(line);
}
}
candidates.removeAll(toDelete);
toDelete.clear();
Set<String> headerFonts = new HashSet<String>();
List<BxLine> candidatesList = Lists.newArrayList(candidates);
for (int x = 0; x < candidatesList.size(); x++) {
BxLine line1 = candidatesList.get(x);
for (int y = x + 1; y < candidatesList.size(); y++) {
BxLine line2 = candidatesList.get(y);
for (int z = y + 1; z < candidatesList.size(); z++) {
BxLine line3 = candidatesList.get(z);
if (line1.getMostPopularFontName().equals(line2.getMostPopularFontName())
&& line3.getMostPopularFontName().equals(line2.getMostPopularFontName())
&& Math.abs(fontPopulation.getZScore(getFontIndex(line1))) > outlFontZScore) {
headerFonts.add(line1.getMostPopularFontName());
}
}
}
}
for (BxPage page : document) {
for (BxZone zone : page) {
if (zone.getLabel().equals(BxZoneLabel.BODY_CONTENT)
|| zone.getLabel().equals(BxZoneLabel.GEN_BODY)) {
for (BxLine line : zone) {
if (looksLikeHeader(line) && headerFonts.contains(line.getMostPopularFontName())) {
candidates.add(line);
}
}
}
}
}
for (BxLine line : candidates) {
if (shouldBeRemoved(
line, heightPopulation, fontPopulation, distancePopulation, indentationPopulation)) {
toDelete.add(line);
}
if (lengthPopulation.getZScore(line.getWidth()) > candMaxLengthZScore2) {
toDelete.add(line);
}
}
candidates.removeAll(toDelete);
toDelete.clear();
for (BxLine line : candidates) {
int i = 0;
for (BxLine line2 : candidates) {
if (line.equals(line2)) {
continue;
}
if (areSimilar(line, line2)) {
i++;
}
}
if (i == 0 || i > maxSimilarLinesCount) {
toDelete.add(line);
for (BxLine line2 : candidates) {
if (areSimilar(line, line2)) {
toDelete.add(line2);
}
}
}
}
candidates.removeAll(toDelete);
candidatesList = new ArrayList<BxLine>();
for (BxPage page : document) {
for (BxZone zone : page) {
for (BxLine line : zone) {
if (candidates.contains(line)) {
candidatesList.add(line);
}
}
}
}
int clusters[] = headersClusterizer.clusterLines(candidatesList);
Set<Integer> keptClusters = new HashSet<Integer>();
for (int clusterIdx = 0; clusterIdx < clusters.length; clusterIdx++) {
int cluster = clusters[clusterIdx];
if (keptClusters.size() < 3) {
keptClusters.add(cluster);
}
if (!keptClusters.contains(cluster)) {
candidates.remove(candidatesList.get(clusterIdx));
}
}
BxContentStructure contentStructure = new BxContentStructure();
BxLine lastHeaderLine = null;
for (BxPage page : document) {
for (BxZone zone : page) {
if (zone.getLabel().equals(BxZoneLabel.BODY_CONTENT)
|| zone.getLabel().equals(BxZoneLabel.GEN_BODY)) {
for (BxLine line : zone) {
if (candidates.contains(line)) {
contentStructure.addFirstHeaderLine(page, line);
lastHeaderLine = line;
} else if (zone.getLabel().equals(BxZoneLabel.BODY_CONTENT)
|| zone.getLabel().equals(BxZoneLabel.GEN_BODY)) {
if (lastHeaderLine == null) {
BxChunk chunk = new BxChunk(new BxBounds(), "--");
BxWord word = new BxWord().addChunk(chunk);
lastHeaderLine = new BxLine().addWord(word);
contentStructure.addFirstHeaderLine(page, lastHeaderLine);
}
contentStructure.addContentLine(lastHeaderLine, line);
}
}
}
}
}
headerLinesCompletener.completeLines(contentStructure);
return contentStructure;
}
private boolean areSimilar(BxLine line1, BxLine line2) {
return line1.getMostPopularFontName().equals(line2.getMostPopularFontName())
&& Math.abs(line1.getHeight() - line2.getHeight()) < maxHeightSimilarity;
}