Check if document has watermark

[HomerWu]

Dear support,

Is there's a way to check a document has watermark when the document opened?

[Tracker Supp-Stefan]

Hello HomerWu,

The thing is that there is no specific way that a 'watermark' is devined inside a PDF file.
It could be base content that is e.g. rotated so that it appears on the diagonal of a page, and is say 60-80% transparent - however this content is not really distinguishable from other base content in the file, so there is no reliable 'test' for whether something is watermark or not, and as such no way for you to detect that at the time you open a file.

Kind regards,
Stefan

[Vasyl-Tracker Dev Team]

Hi, HomerWu.

Stefan is right when we talk about watermarks added in 'dirty' way, directly to the content and without additional info, and therefore - without the proper and reliable way to identify them later.
However, for watermarks added in standard way, via "Add Watermarks" feature in app's UI (in any pdf-app, not just in the Editor) - it is possible to detect the presence of them on the pages:

Code: Select all

PDFXEdit.IPXC_Document coreDoc;
bool bDocHasWatermarks = false;
...

coreDoc.CosDocument.LockDocument();
uint pagesCount = coreDoc.Pages.Count;
for (uint i = 0; i < pagesCount; i++)
{
	PDFXEdit.IPXC_Page page = coreDoc.Pages[i];
	IPXS_PDFVariant pageObj = page.PDFObject;
	IPXS_PDFVariant resObj = pageObj.Dict_Get("Resources");
	if (resObj == null)
		continue;
	IPXS_PDFVariant xoObj = resObj.Dict_Get("XObject");
	if (xoObj == null)
		continue;
	uint xoObjCount = xoObj.Count;
	for (uint j = 0; j < xoObjCount; j++)
	{
		IPXS_PDFVariant it = xoObj[j];
		it = it.Dict_Get("PieceInfo");
		if (it == null)
			break;
		it = it.Dict_Get("ADBE_CompoundType");
		if (it == null)
			break;
		string name = it.Dict_GetName("Private", "");
		if (name == "Watermark")
		{
			bDocHasWatermarks = true;
			break;
		}
	}
	if (bDocHasWatermarks)
		break;	
}

coreDoc.CosDocument.UnlockDocument();