Jesper Juul, an associate professor at The Royal Danish Academy of Fine Arts that has studied the video game market, wrote in his book "Handmade Pixels" that the definition of an indie game is vague, and depends on different subjective considerations. Juul classified three ways games can be considered indie: those that are financially independent of large publishers, those that are aesthetically independent and significantly different of the mainstream art and visual styles used in AAA games, and those that present cultural ideas that are independent from mainstream games. Juul however wrote that ultimately the labeling of a game as "indie" still can be highly subjective and no single rule helps delineate indie games from non-indie ones.