Add Watermark To PDF with C++

While converting an Excel file to PDF, you may have requirements to add a watermark to the PDF file. The following examples show how to add text and image watermarks to PDF while rendering to PDF.

Add text watermark to PDF

You can easily add a text watermark to PDF by specifying text and the corresponding font. Also, you can set alignment, offset, rotation, opacity, foreground/background, and scale to page in RenderingWatermark.

#include <iostream>
#include "Aspose.Cells.h"
using namespace Aspose::Cells;
using namespace Aspose::Cells::Rendering;

int main()
{
    Aspose::Cells::Startup();

    // Prepare a workbook with 3 pages.
    Workbook wb;
    wb.GetWorksheets().Get(0).GetCells().Get(u"A1").PutValue(u"Page1");
    int index = wb.GetWorksheets().Add();
    wb.GetWorksheets().Get(index).GetCells().Get(u"A1").PutValue(u"Page2");
    index = wb.GetWorksheets().Add();
    wb.GetWorksheets().Get(index).GetCells().Get(u"A1").PutValue(u"Page3");
    wb.GetWorksheets().Get(index).GetPageSetup().SetPaperSize(PaperSizeType::PaperA3);

    // Create a font for watermark, and specify bold, italic, color.
    RenderingFont font(u"Calibri", 68);
    font.SetItalic(true);
    font.SetBold(true);
    font.SetColor(Color::Blue());

    // Create a watermark from text and the specified font.
    RenderingWatermark watermark(u"Watermark", font);

    // Specify horizontal and vertical alignment.
    watermark.SetHAlignment(TextAlignmentType::Center);
    watermark.SetVAlignment(TextAlignmentType::Center);

    // Specify rotation.
    watermark.SetRotation(30);

    // Specify opacity.
    watermark.SetOpacity(0.6f);

    // Specify the scale to page (e.g., 100, 50) in percent.
    watermark.SetScaleToPagePercent(50);

    // Specify watermark for rendering to PDF.
    PdfSaveOptions options;
    options.SetWatermark(watermark);

    // Save the workbook with the watermark.
    wb.Save(u"output_text_watermark.pdf", options);

    std::cout << "Workbook saved with watermark successfully!" << std::endl;

    Aspose::Cells::Cleanup();
}

Add image watermark to PDF

You can add an image watermark to PDF just by specifying image bytes of an image. Also, you can set alignment, offset, rotation, opacity, foreground/background, and scale to page in RenderingWatermark.

#include <iostream>
#include "Aspose.Cells.h"
using namespace Aspose::Cells;
using namespace Aspose::Cells::Rendering;

int main()
{
    Aspose::Cells::Startup();

    // Create a workbook with 3 pages
    Workbook wb;
    wb.GetWorksheets().Get(0).GetCells().Get(u"A1").PutValue(u"Page1");
    int index = wb.GetWorksheets().Add();
    wb.GetWorksheets().Get(index).GetCells().Get(u"A1").PutValue(u"Page2");
    index = wb.GetWorksheets().Add();
    wb.GetWorksheets().Get(index).GetCells().Get(u"A1").PutValue(u"Page3");
    wb.GetWorksheets().Get(index).GetPageSetup().SetPaperSize(PaperSizeType::PaperA3);

    // Create a watermark from image (prepare image bytes)
    Vector<uint8_t> imageBytes; // Assume image bytes are prepared
    RenderingWatermark watermark(imageBytes);

    // Specify offset to alignment
    watermark.SetOffsetX(100);
    watermark.SetOffsetY(200);

    // Specify rotation
    watermark.SetRotation(30);

    // Specify watermark to background
    watermark.SetIsBackground(true);

    // Specify opacity
    watermark.SetOpacity(0.6f);

    // Specify the scale to page (e.g., 100, 50) in percent
    watermark.SetScaleToPagePercent(50);

    // Specify watermark for rendering to PDF
    PdfSaveOptions options;
    options.SetWatermark(watermark);

    // Save the workbook with the watermark
    wb.Save(u"output_image_watermark.pdf", options);

    std::cout << "Workbook saved with watermark successfully!" << std::endl;

    Aspose::Cells::Cleanup();
}