Artist Ranjit Dahiya works on a mural of Bolllywood actor Amitabh Bachchan from his classic film Deewar in Mumbai yesterday. Artists from Bollywood Art Project (BAP), an urban public art project, aims to transform the walls in Mumbai through graffiti art influenced by the 70-year-old design tradition of hand-painted Bolllywood posters, to celebrate the centennial of Indian cinema in 2013.