Even if it was captured uncompressed, uncompressed != hidef. Uncompressed is just that, uncompressed. So you'd end up with a multi-gigabyte file that you can store on a blu-ray or HD-DVD disc, but it wouldn't be playable except in raw form. The only way to get it into hidef format would be to upsample it. But even with that, you're not going to get something better than what you started with without a LOT of work (if it's even possible).