unable to put stamp using itext7 using Java lanaguage on only skia generated pdf (shows inverted stamp)

Question

I am unable to put stamp using itext7 using Java language on only skia generated pdf (skia is pdf library used by google; if someone has worked on google docs-> Clicks on Print -> Save as Pdf ). It Stamps incorrectly; if I stamp at top left position of pdf page then it would stamp at bottom left and show (inverted mirror) image and (inverted mirror) text. For all other pdfs it gives correct stamping. It seems pdf generated by skia has missing meta -data.

Answer 1

Since you didn't share any code, nor any document, I created a PDF document from Google docs, and I used the code I wrote in answer to the Itextsharp 7 - Scaled and Centered Image as watermark question to add a Watermark in the center.

The result looked like this:

As you can see in the Document Properties, the original document was created using Skia/PDF m67; modified using iText® 7.1.3.

You need a Watermark in the top left, so I adapted the code like this:

public void createPdf(String src, String dest) throws IOException {
    PdfDocument pdfDoc = new PdfDocument(
            new PdfReader(src), new PdfWriter(dest));
    Document document = new Document(pdfDoc);
    PdfCanvas over;
    PdfExtGState gs1 = new PdfExtGState();
    gs1.setFillOpacity(0.5f);
    int n = pdfDoc.getNumberOfPages();
    Rectangle pagesize;
    ImageData img = ImageDataFactory.create(IMG);
    float iW = img.getWidth();
    float iH = img.getHeight();
    float x, y;

    for (int i = 1; i <= n; i++)
    {
        PdfPage pdfPage = pdfDoc.getPage(i);
        pagesize = pdfPage.getPageSize();

        x = pagesize.getLeft();
        y = pagesize.getTop() - iH;

        over = new PdfCanvas(pdfDoc.getPage(i));

        over.saveState();
        over.setExtGState(gs1);

        over.addImage(img, iW, 0, 0, iH, x, y);

        over.restoreState();
    }
    document.close();
    pdfDoc.close();
}

The result looks like this:

The image isn't mirrored; it's at the top-left position of the page. In short: there doesn't seem to be any problem with PDF's created with Skia/PDF m67.