US Patent 7764286 Creating shadow effects in a two-dimensional imaging space

This specification describes technologies relating to creation of shadow effects in a two-dimensional (2D) imaging space. In general, one aspect of the subject matter described in this specification can be embodied in a method that includes obtaining shadow orientation and length information of a source object in a 2D imaging space. The method also includes creating a shadow effect in the 2D imaging space based on the shadow orientation and length information. The shadow effect resembles a shadow falling on a perceptual three-dimensional (3D) background in the 2D imaging space. Other embodiments of this aspect include corresponding systems, apparatus, and computer program products.