How to convert PointerByReference image to Byte[] then BITMAP using JAVA/JNA?

Question

i'm using JNA to work with a scanner's library "LSAPI.DLL" so, after the scan i get a frontimg parameter which is a Pointer of a Dib format, so i have to convert it to a Byte[] then convert the Byte[] to a bitmap and finally save the scanned image on my desktop to test.

this is the method that gave me the Pointer of the frontimg :

int a1 = lsApi.LSReadImage(hConnect.getValue(), fgWindow, LsApiConst.CLEAR_ALL_BLACK, (char) LsApiConst.SIDE_FRONT_IMAGE, LsApiConst.READMODE_BRUTTO, NrDoc, frontimg, backimg, R1, R2);

i tried to start with this but it doesn't work :

Pointer p = frontimg.getValue();
byte[] buffer = p.getByteArray(0, frontimg.getValue().SIZE);
BufferedImage img = ImageIO.read(new ByteArrayInputStream(buffer));
    ImageIO.write(img,"BMP", new File("D:/image.BMP")); 
    System.out.println("image created");

is there any way to proceed ?