In a lengthy and fascinating article in the Indian magazine Open, Devika Bakshi explains why the close-ups of penises were pixelated in the Indian version of Chester Brown's Paying For It, while the long-shots, and other body parts, were left alone.
Indian law says a work is obscene "if it is lascivious or appeals to the prurient interest" or if its effect is to "deprave and corrupt" anyone who sees it. There are exceptions, though, for works with redeeming features (I'm paraphrasing here; the full text is at the link), works that are used for religious purposes and "any representation sculptured, engraved, painted or otherwise represented on or in (i) any ancient monument within the meaning of the Ancient Monuments and Archaeological Sites and Remains Act, 1958 (24 of 1958)."
That means all versions of the Kama Sutra, even the cheesy ones, are protected, but more modern works of a similar nature are not. Police recently raided the Hachette offices because they imported Letters to Penthouse and a book on sex positions.
With regard to Paying For It, Brown's frank graphic memoir of his encounters with prostitutes, the book itself doesn't seem to be a problem so much as the specific imagery. VK Karthika, the publisher and editor-in-chief of HarperCollins India, explained that Brown's penises were obscured not because they would run afoul of the censorship laws but because she was "making sure the text was not hijacked away from its context" into a discussion about obscenity. She seems to have failed, because we're talking about it anyway, but Bakshi's article is a fascinating look at the distinctions people draw in a culture with legal prohibitions on obscenity.