I have refer to the dictionary. It has the meaning of "take the responsibility of .." The background is: the scientist has invented an kind of technique. He can translating the painting into virtual world just like creating the Second Life Avatar. By doing this he can analyse whether the light in the painting is natural or created by the studio. I think this sentence means he begin to analyse the paint<> using this kind of technology. and in this sentence ， “the scientist has taken on "Las Meninas"by Velazquez, possibly the greatest picture ever made”, I think it can be translated to"decide to do "better. Because if the work is not assigned by others ,it should not be equals as"undertake".
what do you think of it? "take the responsibility "or "decide to do"?