Stream Read Error

Dear All,
I need to copy the content of TMemoryStream to an TBArray =  Array of
Byte.

I have the following code, and I am getting Stream Read Error.

     MS:=TMemoryStream.Create;
     imgView.IO.SaveToStreamJpeg(MS);
     SZ:=MS.Size;
     SetLength(img,SZ);
     MS.ReadBuffer(img, SZ);

Where imgView is a TImageEn component that has a JPG file loaded
within it.

Any advise?