public static byte[] CropPdf(float llx, float lly, float urx, float ury, byte[] fileData) { PdfReader reader = new PdfReader(fileData); int n = reader.NumberOfPages; PdfDictionary pageDict; PdfRectangle rect = new PdfRectangle(llx, lly, urx, ury); for (int i = 1; i <= n; i++) { pageDict = reader.GetPageN(i); pageDict.Put(PdfName.CROPBOX, rect); } using (MemoryStream ms = new MemoryStream()) { using (PdfStamper stamper = new PdfStamper(reader, ms)) { } return ms.ToArray(); } }