Micro 4/3 1.4 Teleconverter

It is a crop, then a re-sample, albeit an extremely sophisticated one, back to full resolution. 2x filters are easy to implement especially with high pixel density, the more data the better. I don't think anyone has figured out what type of 2x filter is being used but it's easily one of the best implementations out there. I can tell you now it is far better than the Bicubic filters in Photoshop.