Extracting charts from Excel documents using POI or HSSF?

I've got a bunch of Excel documents that have data on one sheet and a chart produced from the data on another sheet. I'd like to take those documents and produce a series of HTML pages from them. Using POI (or HSSF) know I can read the data from the documents and produce a chart using some charting e开发者_开发技巧ngine. But the customer's not happy with the output of any engine I through this at and would be just happy with the graph that is already in the Excel spreadsheet. Does anyone know how I can extract that chart from Excel as a JPEG/PNG/GIF?

There is no chart "picture" stored in Excel,you must render your chart yourself if you are not using Excel.