Mesh-based computation for solving bas-relief reconstruction from editable normal image

Abstract

As a representative art form between drawing and sculpture, bas-relief is widely used in media for signs, narratives, and decorations. Recent works focus on producing bas-reliefs with fewer interactions and manual efforts. However, they are limited by the large storage size of modeling results, that hinders fast rendering and downstream geometry processing (e.g. bas-relief editing). We propose a mesh-based modeling framework to generate progressive bas-reliefs with different resolutions from editable normal images. Specifically, (1) the normal image is down-sampled to eliminate redundant information but with its visual saliency preserved; (2) to avoid adding any integrability constraints, the editable normal image is changed to mesh representation as the discrete geometry processing setup; (3) surface-from-gradients (SfG) is improved to fit our bas-relief reconstruction with both height and normal constraints. Our method can produce more portable bas-reliefs with smaller sizes for fast visualization, geometry processing, and feeding CNC and 3D printing devices in practice. Experiments show that our method competes favorably with existing methods in visual quality and surface accuracy.