我有一个包含很多不可见路径的 pdf。由于路径的数量稍后会产生问题,因此我想删除具有白色的路径。
到目前为止,我正在尝试使用ContentScanner
:
public class FilterWhitePathScanner implements Scanner {
private static final Logger LOG = LoggerFactory.getLogger(FilterWhitePathScanner.class);
private int count = 0;
public void scan(ContentScanner level) {
if (level == null)
return;
while (level.moveNext()) {
ContentObject object = level.getCurrent();
if (object instanceof ContainerObject) {
// Scan the inner level!
scan(level.getChildLevel());
} else if (object instanceof org.pdfclown.documents.contents.objects.Path) {
AffineTransform ctm = level.getState().getCtm();
Color<?> strokeColor = level.getState().getStrokeColor();
Color<?> fillColor = level.getState().getFillColor();
if (checkWhite(fillColor) && checkWhite(strokeColor)) {
level.remove();
} else {
LOG.info("Stroke Color " + strokeColor + " - Fill Color " + fillColor);
}
} else {
LOG.info("Object:" + object);
}
}
}
它可以正确识别路径,但最终这些路径并未从 PDF 中删除。这里是处理 PDF 的代码(它只从源 pdf 中提取一页):
Document targetDoc = new File().getDocument();
targetDoc.getPages().add(sourceDoc.getPages().get(pageNum).clone(targetDoc));
Page page = targetDoc.getPages().get(0);
Contents contents = page.getContents();
FilterWhitePathScanner filterWhitePathScanner = new FilterWhitePathScanner();
filterWhitePathScanner.scan(new ContentScanner(contents));
LOG.info("White Paths: " + filterWhitePathScanner.getCount());
targetDoc.getFile().save(tempFilePath.toFile(), SerializationModeEnum.Standard);
保存的 PDF 文件仍然包含我试图删除的路径。最后如何从 PDF 中删除对象?
谢谢,托马斯