//Instantiating a Workbook object
Workbook workbook = new Workbook();

Worksheet sheet = workbook.getWorksheets().get(0);

//Adding a picture at the location of a cell whose row and column indices
//are 5 in the worksheet. It is "F6" cell
int pictureIndex = sheet.getPictures().add(5,5,"data/xlsx4j/greentick.png");
Picture picture = sheet.getPictures().get(pictureIndex);

public static void main(String[] args) throws Exception {

    String outputfilepath = System.getProperty("user.dir") + "/data/xlsx4j/AddImage-Xlsx4j.xlsx";
    String imagefilePath  = System.getProperty("user.dir") + "/data/xlsx4j/greentick.png" ;

    SpreadsheetMLPackage pkg = SpreadsheetMLPackage.createPackage();
    WorksheetPart worksheet = pkg.createWorksheetPart(new PartName("/xl/worksheets/sheet1.xml"), "Sheet1", 1);

    // Create Drawing part and add to sheet 
    Drawing drawingPart = new Drawing();
    Relationship drawingRel = worksheet.addTargetPart(drawingPart);

    // Add anchor XML to worksheet
    org.xlsx4j.sml.CTDrawing drawing = org.xlsx4j.jaxb.Context.getsmlObjectFactory().createCTDrawing(); 
        worksheet.getJaxbElement().setDrawing(drawing); 
            drawing.setId( drawingRel.getId() );        

    // Create image part and add to Drawing part
    BinaryPartAbstractImage imagePart 
        = BinaryPartAbstractImage.createImagePart(pkg, drawingPart, 
                FileUtils.readFileToByteArray(new File(imagefilePath) ));
    String imageRelID = imagePart.getSourceRelationship().getId();

    // Create and set drawing part content
    // Take your pick ..
    // .. build it using code
//        drawingPart.setJaxbElement(
//              buildDrawingPartContentUsingCode(imageRelID));
    // .. or build it from an XML string
    drawingPart.setJaxbElement(
            buildDrawingPartContentFromXmlString(imageRelID));

    // Save the xlsx
    SaveToZipFile saver = new SaveToZipFile(pkg);
    saver.save(outputfilepath);
    System.out.println("\n\n done .. " + outputfilepath);   
}

/**
 * This code generated using http://webapp.docx4java.org/OnlineDemo/PartsList.html
 * "Method 1"
 */
public static CTDrawing buildDrawingPartContentUsingCode(String imageRelID) {

    org.docx4j.dml.spreadsheetdrawing.ObjectFactory dmlspreadsheetdrawingObjectFactory = new org.docx4j.dml.spreadsheetdrawing.ObjectFactory();

    CTDrawing drawing = dmlspreadsheetdrawingObjectFactory.createCTDrawing(); 
//      JAXBElement<org.docx4j.dml.spreadsheetdrawing.CTDrawing> drawingWrapped = dmlspreadsheetdrawingObjectFactory.createWsDr(drawing); 
        // Create object for twoCellAnchor
        CTTwoCellAnchor twocellanchor = dmlspreadsheetdrawingObjectFactory.createCTTwoCellAnchor(); 
        drawing.getEGAnchor().add( twocellanchor); 
            // Create object for clientData
            CTAnchorClientData anchorclientdata = dmlspreadsheetdrawingObjectFactory.createCTAnchorClientData(); 
            twocellanchor.setClientData(anchorclientdata); 
            // Create object for pic
            CTPicture picture = dmlspreadsheetdrawingObjectFactory.createCTPicture(); 
            twocellanchor.setPic(picture); 
    org.docx4j.dml.ObjectFactory dmlObjectFactory = new org.docx4j.dml.ObjectFactory();
                // Create object for blipFill
                CTBlipFillProperties blipfillproperties = dmlObjectFactory.createCTBlipFillProperties(); 
                picture.setBlipFill(blipfillproperties); 
                    // Create object for blip
                    CTBlip blip = dmlObjectFactory.createCTBlip(); 
                    blipfillproperties.setBlip(blip); 
                        blip.setCstate(org.docx4j.dml.STBlipCompression.NONE);
                        blip.setEmbed( imageRelID ); 
                        // Create object for extLst
                        CTOfficeArtExtensionList officeartextensionlist = dmlObjectFactory.createCTOfficeArtExtensionList(); 
                        blip.setExtLst(officeartextensionlist); 
                            // Create object for ext
                            CTOfficeArtExtension officeartextension = dmlObjectFactory.createCTOfficeArtExtension(); 
                            officeartextensionlist.getExt().add( officeartextension); 
                                officeartextension.setUri( "{28A0092B-C50C-407E-A947-70E740481C1C}"); 
                        blip.setLink( ""); 
                    // Create object for stretch
                    CTStretchInfoProperties stretchinfoproperties = dmlObjectFactory.createCTStretchInfoProperties(); 
                    blipfillproperties.setStretch(stretchinfoproperties); 
                        // Create object for fillRect
                        CTRelativeRect relativerect = dmlObjectFactory.createCTRelativeRect(); 
                        stretchinfoproperties.setFillRect(relativerect); 
                            relativerect.setR( new Integer(0) );
                            relativerect.setT( new Integer(0) );
                            relativerect.setL( new Integer(0) );
                            relativerect.setB( new Integer(0) );
                // Create object for spPr
                CTShapeProperties shapeproperties = dmlObjectFactory.createCTShapeProperties(); 
                picture.setSpPr(shapeproperties); 
                    // Create object for xfrm
                    CTTransform2D transform2d = dmlObjectFactory.createCTTransform2D(); 
                    shapeproperties.setXfrm(transform2d); 
                        transform2d.setRot( new Integer(0) );
                        // Create object for off
                        CTPoint2D point2d = dmlObjectFactory.createCTPoint2D(); 
                        transform2d.setOff(point2d); 
                            point2d.setY( 0 );
                            point2d.setX( 0 );
                        // Create object for ext
                        CTPositiveSize2D positivesize2d = dmlObjectFactory.createCTPositiveSize2D(); 
                        transform2d.setExt(positivesize2d); 
                            positivesize2d.setCx( 714375 );
                            positivesize2d.setCy( 714375 );
                    // Create object for prstGeom
                    CTPresetGeometry2D presetgeometry2d = dmlObjectFactory.createCTPresetGeometry2D(); 
                    shapeproperties.setPrstGeom(presetgeometry2d); 
                        // Create object for avLst
                        CTGeomGuideList geomguidelist = dmlObjectFactory.createCTGeomGuideList(); 
                        presetgeometry2d.setAvLst(geomguidelist); 
                        presetgeometry2d.setPrst(org.docx4j.dml.STShapeType.RECT);
                // Create object for nvPicPr
                CTPictureNonVisual picturenonvisual = dmlspreadsheetdrawingObjectFactory.createCTPictureNonVisual(); 
                picture.setNvPicPr(picturenonvisual); 
                    // Create object for cNvPr
                    CTNonVisualDrawingProps nonvisualdrawingprops = dmlObjectFactory.createCTNonVisualDrawingProps(); 
                    picturenonvisual.setCNvPr(nonvisualdrawingprops); 
                        nonvisualdrawingprops.setDescr( ""); 
                        nonvisualdrawingprops.setName( "Picture 1"); 
                        nonvisualdrawingprops.setId( 2 );
                    // Create object for cNvPicPr
                    CTNonVisualPictureProperties nonvisualpictureproperties = dmlObjectFactory.createCTNonVisualPictureProperties(); 
                    picturenonvisual.setCNvPicPr(nonvisualpictureproperties); 
                        // Create object for picLocks
                        CTPictureLocking picturelocking = dmlObjectFactory.createCTPictureLocking(); 
                        nonvisualpictureproperties.setPicLocks(picturelocking); 
                picture.setMacro( ""); 
            // Create object for to
            CTMarker marker = dmlspreadsheetdrawingObjectFactory.createCTMarker(); 
            twocellanchor.setTo(marker); 
                marker.setCol(1);
                marker.setColOff( 104775 );
                marker.setRow(3);
                marker.setRowOff( 142875 );
            // Create object for from
            CTMarker marker2 = dmlspreadsheetdrawingObjectFactory.createCTMarker(); 
            twocellanchor.setFrom(marker2); 
                marker2.setCol(0);
                marker2.setColOff( 0 );
                marker2.setRow(0);
                marker2.setRowOff( 0 );
            twocellanchor.setEditAs(org.docx4j.dml.spreadsheetdrawing.STEditAs.ONE_CELL);

//      return drawingWrapped;
    return drawing;
}   

/**
 * This code generated using http://webapp.docx4java.org/OnlineDemo/PartsList.html
 * "Method 2"
 */
public static CTDrawing buildDrawingPartContentFromXmlString(String imageRelID) throws JAXBException {

    String openXML = "<xdr:wsDr xmlns:a=\"http://schemas.openxmlformats.org/drawingml/2006/main\" xmlns:a14=\"http://schemas.microsoft.com/office/drawing/2010/main\" xmlns:xdr=\"http://schemas.openxmlformats.org/drawingml/2006/spreadsheetDrawing\" xmlns:r=\"http://schemas.openxmlformats.org/officeDocument/2006/relationships\">"
            + "<xdr:twoCellAnchor editAs=\"oneCell\">"
                + "<xdr:from>"
                    + "<xdr:col>0</xdr:col>"
                    + "<xdr:colOff>0</xdr:colOff>"
                    + "<xdr:row>0</xdr:row>"
                    + "<xdr:rowOff>0</xdr:rowOff>"
                +"</xdr:from>"
                + "<xdr:to>"
                    + "<xdr:col>1</xdr:col>"
                    + "<xdr:colOff>104775</xdr:colOff>"
                    + "<xdr:row>3</xdr:row>"
                    + "<xdr:rowOff>142875</xdr:rowOff>"
                +"</xdr:to>"
                + "<xdr:pic>"
                    + "<xdr:nvPicPr>"
                        + "<xdr:cNvPr id=\"2\" name=\"Picture 1\"/>"
                        + "<xdr:cNvPicPr>"
                            + "<a:picLocks noChangeAspect=\"1\"/>"
                        +"</xdr:cNvPicPr>"
                    +"</xdr:nvPicPr>"
                    + "<xdr:blipFill>"
                        + "<a:blip r:embed=\"" + imageRelID + "\">"
                            + "<a:extLst>"
                                + "<a:ext uri=\"{28A0092B-C50C-407E-A947-70E740481C1C}\">"
                                    + "<a14:useLocalDpi val=\"0\"/>"
                                +"</a:ext>"
                            +"</a:extLst>"
                        +"</a:blip>"
                        + "<a:stretch>"
                            + "<a:fillRect/>"
                        +"</a:stretch>"
                    +"</xdr:blipFill>"
                    + "<xdr:spPr>"
                        + "<a:xfrm>"
                            + "<a:off x=\"0\" y=\"0\"/>"
                            + "<a:ext cx=\"714375\" cy=\"714375\"/>"
                        +"</a:xfrm>"
                        + "<a:prstGeom prst=\"rect\">"
                            + "<a:avLst/>"
                        +"</a:prstGeom>"
                    +"</xdr:spPr>"
                +"</xdr:pic>"
                + "<xdr:clientData/>"
            +"</xdr:twoCellAnchor>"
        +"</xdr:wsDr>";

    return (CTDrawing)XmlUtils.unwrap(
            XmlUtils.unmarshalString(openXML)); 
}