Good article from the WSJ: Facial-Recognition Software Meets Its Match: Barnyard Animals, money quote:
“It’s not like you can tell a donkey to stand still and raise its chin up slightly,” said Mr. Chen. “That’s just impossible.”
******-*********** ******** *** *******, ***** ** commercially *********, *****’* ******* *** **** degree ** ***** *** ******** ** similar ********** *** ******. *** ******** take ****** ** **** * *************** and *** ******* ****-********** ****** ** more ******* ***** **** ********* ******.
****** ***** ******* ******** ** ********* points, **** **** **** ******, ** derive ********** **** *** ******* ******* levels ** ***************, ********** ***.