FileInputStream FIS=new FileInputStream("C:\\test.doc");
        HWPFDocument wb=null;
        wb = new HWPFDocument(FIS);      
        FIS.close();

        File FI=new File("C:\\t.png");
        byte bim[]=new byte[(int)FI.length()];
        FileInputStream FIM=new FileInputStream(FI);
        FIM.read(bim);
        FIM.close();
        EscherBlipRecord ebr=new EscherBlipRecord();
        ebr.setPictureData(bim);
        Picture px=new Picture(ebr);  
        wb.getPicturesTable().getAllPictures().set(0, px);
        
        FileOutputStream FOS=null;
        FOS = new FileOutputStream("C:\\test1.doc");
        wb.write(FOS);
        FOS.close();

        XWPFDocument wb=null;
        try {
            wb = new XWPFDocument();
        } catch (Exception ex) {
        }        
        XWPFParagraph p = wb.createParagraph();
        XWPFRun r = p.createRun();
        int format = XWPFDocument.PICTURE_TYPE_PNG;
        r.setText("проба");
        r.addBreak();
        r.addBreak(BreakType.PAGE);
        r.addPicture(new FileInputStream(outFileString), format, outFileString, Units.toEMU(200), Units.toEMU(100));
        
        FileOutputStream FOS=null;
        try {
            FOS = new FileOutputStream("C:\\test1.docx");
        } catch (Exception ex) {
            ex.printStackTrace();
        }
        try {
            wb.write(FOS);
        } catch (Exception ex) {
            ex.printStackTrace();
        }
        try {
            FOS.close();
        } catch (Exception ex) {
            ex.printStackTrace();
        }

Selection.InlineShapes.AddPicture