是否可以使用PDFBox创建带标签的PDF(PDF/UA)?看起来PDFBox有一个应用程序接口(org.apache.pdfbox.pdmodel.documentinterchange.taggedpdf
包),但我找不到任何教程或代码示例。
使用下面的代码,我生成了一个包含图像的PDF文件,屏幕阅读器NVDA (在我的例子中)识别它并读取'...图形替代描述‘。然而,可访问性检查器PAC 2显示了一个错误:“未标记图像对象”。
PDDocument doc = new PDDocument();
PDPage page = new PDPage();
doc.addPage(page);
PDDocumentCatalog documentCatalog = doc.getDocumentCatalog();
PDImageXObject pdImage = PDImageXObject.createFromFile(imagePath, doc);
PDPageContentStream contents = new PDPageContentStream(doc, page);
contents.drawImage(pdImage, 100, 600, pdImage.getWidth() / 2, pdImage.getHeight() / 2);
contents.close();
PDStructureTreeRoot treeRoot = new PDStructureTreeRoot();
PDStructureElement structureElement = new PDStructureElement(StandardStructureTypes.Figure, treeRoot);
structureElement.setPage(page);
PDMarkedContent markedImg = new PDMarkedContent(COSName.IMAGE, new COSDictionary());
markedImg.addXObject(pdImage);
structureElement.appendKid(markedImg);
structureElement.setAlternateDescription("Alternate Description");
treeRoot.appendKid(structureElement);
documentCatalog.setStructureTreeRoot(treeRoot);
// ....
doc.save(fileName);
你能提供一些关于这个主题的解释或/和代码示例吗?
发布于 2018-03-24 22:49:41
我提供了一个工作示例,它演示了如何使用PDF2:https://github.com/martinlovell/accessible-pdfbox-example创建可访问的PDFBox
问题中的代码中缺少一些东西。标记的内容需要alt文本,我相信您需要为标记的内容使用mcid。
示例项目更详细地演示了您所需要的内容。
它应该是这样的:
PDPageContentStream contents = new PDPageContentStream(doc, page);
// the content in the stream needs an id
int mcid = 5;
COSDictionary dictionary = new COSDictionary();
dictionary = new COSDictionary();
dictionary(COSName.MCID, mcid);
// wrap image drawing in marked content
contents.beginMarkedContent(COSName.IMAGE, PDPropertyList.create(dictionary));
contents.drawImage(pdImage, 100, 600, pdImage.getWidth() / 2, pdImage.getHeight() / 2);
contents.endMarkedContent();
contents.close();
PDStructureTreeRoot treeRoot = new PDStructureTreeRoot();
documentCatalog.setStructureTreeRoot(treeRoot);
PDStructureElement structureElement = new PDStructureElement(StandardStructureTypes.Figure, treeRoot);
structureElement.setPage(page);
structureElement.setAlternateDescription("Alternate Description");
// Set alt text on marked content for structure.
// This is the dictionary with the mcid used in beginMarkedContent.
dictionary.setString(COSName.ALT, "Alternate Description");
PDMarkedContent markedImg = new PDMarkedContent(COSName.IMAGE, dictionary);
markedImg.addXObject(pdImage);
structureElement.appendKid(markedImg);
https://stackoverflow.com/questions/39872854
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