Hello,
//Open document
Aspose.Pdf.Document pdfDocument = new Aspose.Pdf.Document(inputPdfFile);<span style="color:green;">//Create image stamp</span> Aspose.Pdf.<span style="color:#2b91af;">ImageStamp</span> imageStamp = <span style="color:blue;">new</span> Aspose.Pdf.<span style="color:#2b91af;">ImageStamp</span>(imageFile); imageStamp.Background = background; imageStamp.XIndent = lowerLeftX; imageStamp.YIndent = lowerLeftY; imageStamp.Height = upperRightY - lowerLeftY; imageStamp.Width = upperRightX - lowerLeftX; <span style="color:green;">//Add stamp to particular page</span> pdfDocument.Pages[pageNumber].AddStamp(imageStamp); <span style="color:green;">//Save output document</span> pdfDocument.Save(outputPdfFile);</pre><pre style="font-family: Consolas; font-size: 13px; background: white;"><span style="font-family: 'Times New Roman'; font-size: medium; white-space: normal;">My problem is that when the GIF has transparent background, this code puts a BLACK background on the image.</span></pre><pre style="font-family: Consolas; font-size: 13px; background: white;"><span style="font-family: 'Times New Roman'; font-size: medium; white-space: normal;">Stamping the same files with iTextSharp does the job perfectly.</span></pre><pre style="font-family: Consolas; font-size: 13px; background: white;"><br></pre></div>