Photoshop Small Image Enlarging - Addendum.
After reviewing the previous entry, I must agree that the 4x truffle doesn't look very good at all. Also, I completely screwed up the size attributes, so there was some browser resizing occurring. Mea culpa. I offer the same method applied to a truffle enlarged to only twice it's original size.
And here is a truffle enlarge to only 1.5 times it's original size. That's not too shabby, and probably the best we can do without getting a source vector image or re-creating the truffle.