How can you achieve this mosaic like effect in Photoshop?
How can i achieve this effect in photoshop? is it hand drawn in illustrator or can it be done using a couple of filters and gradients in photoshop ?
I found that picture while going through this page. http://www.digitalartserved.com/gallery/Various-Illustrations-2013/10068071
I would think he probably starts with a basic portrait (drawn or live-traced), and then applies the color layers manually.
It's hard to tell, and there's no reason why you can't ask the author himself, but I'm guessing it's manual work because of these two pictures in his website's profile page:
And you can also see the same amount of hand-crafted detail in this other piece from his portfolio: