图像上方的文本和图像覆盖的文本之间的区别

Question

我已经测试了in this thread 提供的代码。它可以找到包含在图像边界框中的所有文本元素。但是，您如何区分图片背后的文字和图片上方的文字呢？

Answer 1

下面粘贴的是old answer mentioned above的代码，移植到PDFBox 2.0.24。主要变化是：

• 已添加getName() 方法
• context.processSubStream 替换为 context.showForm
• PDXObjectForm、PDXObjectImage 替换为新的类名PDFormXObject、PDImageXObject。
• drawer.getResources().getXObjects(); 替换为 drawer.getResources().getXObjectNames() 并且对 XObjects 集合的迭代基于 getXObjectNames() 返回值。

public final class CoveredText extends OperatorProcessor
{
    @Override
    public void process(Operator operator, List<COSBase> operands) throws IOException{
        PDFVisibleTextStripper drawer = (PDFVisibleTextStripper)context;
        for (COSName objectName: drawer.getResources().getXObjectNames()) {
            PDXObject xobject = drawer.getResources().getXObject(objectName);
            if ( xobject == null )
            {
                System.out.println("CoveredText.process Can't find the XObject for '"+objectName.getName()+"'");
            }
            else if( xobject instanceof PDImageXObject )
            {
                System.out.println("CoveredText.process " + objectName.getName()+" is a PDImageXObject");
                drawer.hide(objectName.getName());
            }
            else if(xobject instanceof PDFormXObject)
            {                   
                PDFormXObject form = (PDFormXObject)xobject;
                System.out.println("CoveredText.process " + objectName.getName()+" is a PDFormXObject at localtion " + form.getBBox().toString());
                Matrix matrix = form.getMatrix();
                if (matrix != null) 
                {
                    Matrix xobjectCTM = matrix.multiply( context.getGraphicsState().getCurrentTransformationMatrix());
                    context.getGraphicsState().setCurrentTransformationMatrix(xobjectCTM);
                }
                context.showForm(form);                    
            }               
        }
    } 
    @Override
    public String getName() {
        return "Do";
    }
}