Detail-Preserving Bas-relief on Surface from 3D Scene

A novel algorithm for making the bas-relief from 3D shape onto a curved surface is proposed in order to preserve relief details and get smooth relief-background transitions.Firstly,a continuous gradient field is obtained by special treatment on the silhouettes,which are located by Canny operator.Secondly,a flattened shape is achieved by compressing the magnitude of the gradient using a proposed non-linear function.Subsequently,the details on the original 3D shape are maintained and also enhanced using the bilateral filtering on the gradient domain.Finally,the bas-relief on curved surface is reconstructed from the gradient domain by solving an integral equation.In order to eliminate the steps between relief and background,the background surface is associated to the equation as an optimal condition.The equation is solved accurately in frequency field with no need to set iteration stopping criteria by taking advantages of differential properties of Fourier transformation.The height of bas-relief,the detail sharpness and the transition smoothness can be effectively controlled by tuning the parameters.The experiments demonstrate that the parameters in the algorithm have intuitive geometry meaning,and the obtained bas-relief owns distinct details and smooth relief-background transitions.