Unicode C Requires Chilkat v11.7.0+

Add an Image (Logo) Watermark to a PDF

See more PDF Watermark Examples

Demonstrates an image watermark placed in a corner of every page. The image is a PNG or JPEG given either by path ("image.path") or, as here, as base64 in the JSON itself ("image.base64"), which suits a server that keeps its logo in a database rather than on disk. PNG transparency is kept. Giving only a width keeps the aspect ratio, and the units member says those numbers are inches rather than points. Unicode C

#include <C_CkPdfW.h>
#include <C_CkJsonObjectW.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkPdfW pdf;
    HCkJsonObjectW json;
    HCkJsonObjectW jsonOut;

    success = FALSE;

    //  This example requires the Chilkat API to have been previously unlocked.
    //  See Global Unlock Sample for sample code.

    //  The PDF used in this example is available at four_pages.pdf

    pdf = CkPdfW_Create();
    success = CkPdfW_LoadFile(pdf,L"qa_data/pdf/four_pages.pdf");
    if (success == FALSE) {
        wprintf(L"%s\n",CkPdfW_lastErrorText(pdf));
        CkPdfW_Dispose(pdf);
        return;
    }

    json = CkJsonObjectW_Create();
    CkJsonObjectW_UpdateString(json,L"type",L"image");

    //  A small PNG logo, base64 encoded.  Use "image.path" instead to name a PNG or JPEG file:
    //     ignore = json.UpdateString("image.path","logo.png");
    CkJsonObjectW_UpdateString(json,L"image.base64",L"iVBORw0KGgoAAAANSUhEUgAAAGAAAAAgCAYAAADtwH1UAAAApElEQVR42u3a7QmAIBgAYTdpo/ZphhZti6IBylLrlXoO/G3cIeFHSgAAFDKM08rCy8Jzg6Ug8UJ0JF+EDuSXRGgxX8+jufxlTk0nFuCCiF360aidXICMiDP5uQgCXAxQI782ggAHEu7IP4sgQOcBIMA35ItgBQhQEqBmtbX6xl//hAUI3gcIELwTFiD4LEiA4NNQAYLvA+BGzJ0wvIrwLggA8DgbwPbrr8c7+lkAAAAASUVORK5CYII=");

    //  The size to draw it at.  Give only the width and the height follows the aspect ratio.
    CkJsonObjectW_UpdateString(json,L"units",L"in");
    CkJsonObjectW_UpdateNumber(json,L"image.width",L"1.5");

    //  Bottom-right, half an inch in from the page edges.
    CkJsonObjectW_UpdateString(json,L"position.align",L"bottomRight");
    CkJsonObjectW_UpdateNumber(json,L"position.margin",L"0.5");
    CkJsonObjectW_UpdateNumber(json,L"opacity",L"0.85");
    CkJsonObjectW_UpdateString(json,L"id",L"logo");

    jsonOut = CkJsonObjectW_Create();
    success = CkPdfW_Watermark(pdf,L"add",json,jsonOut);
    if (success == FALSE) {
        wprintf(L"%s\n",CkPdfW_lastErrorText(pdf));
        CkPdfW_Dispose(pdf);
        CkJsonObjectW_Dispose(json);
        CkJsonObjectW_Dispose(jsonOut);
        return;
    }

    wprintf(L"id: %s pages: %s\n",CkJsonObjectW_stringOf(jsonOut,L"id"),CkJsonObjectW_stringOf(jsonOut,L"pages"));

    success = CkPdfW_WriteFile(pdf,L"qa_output/four_pages_logo.pdf");
    if (success == FALSE) {
        wprintf(L"%s\n",CkPdfW_lastErrorText(pdf));
        CkPdfW_Dispose(pdf);
        CkJsonObjectW_Dispose(json);
        CkJsonObjectW_Dispose(jsonOut);
        return;
    }

    //  Sample output:

    //  id: logo pages: 1-4


    CkPdfW_Dispose(pdf);
    CkJsonObjectW_Dispose(json);
    CkJsonObjectW_Dispose(jsonOut);

    }