I don't need to look very far. As someone who has used Photoshop extensively, I'd estimate that any combination of Unsharp Mask, Smart Sharpen, and / or High Pass filters have been used on that image. As a picture of a genuine coin I'd always go with the London Coins image.
The blue is a joke. Reminds me of nothing so much as Coin Monthly's Year Book images at the head of each type in the Blue Pages - the isolation of the main design, legend, and rim, with the fields just a blank blue. But they weren't selling coins, just illustrating the different types.