// The drawing group record always exists at the top level, so we won't need to do this recursively.
List<HSSFPictureData> pictures = new ArrayList<HSSFPictureData>();
Iterator<Record> recordIter = workbook.getRecords().iterator();
while (recordIter.hasNext())
{
Record r = recordIter.next();
if (r instanceof AbstractEscherHolderRecord)
{
((AbstractEscherHolderRecord) r).decode();
List<EscherRecord> escherRecords = ((AbstractEscherHolderRecord) r).getEscherRecords();
searchForPictures(escherRecords, pictures);