Search code examples
parsingextractpdfboxsuperscriptsentence

Excluding super script when extracting text from pdf


I have extracted text from pdf line by line using pdfbox, to process it with my algorithm by sentences.

I am recognizing the sentences by using period(.) followed by a word whose first letter is capital. Here the issue is, when a sentence ends with a word which has superscript, extractor treats it as a normal character and places it next to period(.)

For example: expression "2 power 22" when appeared as a last word in a sentence i.e. with a period, it has been extracted as 2.22 which makes it difficult to identify the end of sentence.

Please suggest a solution to get rid of super script or a different logic to identify the end of sentence.

Thanks.


Solution

  • I am answering my own questions, as some may get directed here.

    I had solved this according to @mkl suggestion. After observing the result of getYScale() in PDFStreamEngine.java, I have come to a conclusion that the size of superscript was less than 8.9663. so I had kept a condition in the PDFStreamEngine.java before creating a TextPosition, which will be processed by PDFTextStripper.java. The code is below:


    if(textXctm.getYScale()>=8.9663) {
        processTextPosition(
            new TextPosition(
                pageRotation,
                pageWidth,
                pageHeight,
                textMatrixStart,
                endXPosition,
                endYPosition,
                totalVerticalDisplacementDisp,
                widthText,
                spaceWidthDisp,
                c,
                codePoints,
                font,
                fontSizeText,
                (int)(fontSizeText * textMatrix.getXScale())
        ));
    }
    

    Let me know if my approach has any flaws in eliminating only the superscripts. Thanks.