Synthesizing solid particle textures via a visual hull algorithm

Numerous techniques have been proposed to successfully synthesize two-dimensional (2D) textures in terms of quality and performance. Three-dimensional (3D) or solid texture synthesis, on the other hand, remains relatively unexplored due to its higher complexity. There are several types of existing algorithms for solid texture synthesis, and among them, the outstanding work by Jagnow et al. opens a new door for solid texture synthesis of discrete particles; however, their work leaves two important issues unaddressed. First, without the help of stereology, users need to explicitly provide the 3D shapes of target particles for synthesis. Second, the locations and orientations of the 3D particles are resolved by a simulated annealing method, which is intrinsically a non-deterministic approach, and thus the optimality is not always guaranteed. To solve the shape problem, we propose a simple algorithm that applies the idea of visual hulls to approximate the shapes of 3D particles when only a 2D image is given; to solve the location and orientation problem, we design a deterministic algorithm that can place these desired 3D particles in space more properly. Additionally we also propose a method to further couple the color and size information of particles to achieve an even better resemblance to the 2D image.