View synthesis for virtual exhibition of impasto artworks using spherical harmonics

The growing use of digital technologies in artistic presentation has highlighted the limitations of traditional 2D documentation, which cannot capture view-dependent optical characteristics essential for experiencing textured oil paintings. We present what is believed to be a novel approach for interactive virtual exhibition of impasto artworks using image synthesis inspired by Gaussian splatting techniques. A spherical harmonics (SH)-based framework is proposed to encode the bidirectional reflectance distribution function of artwork surfaces, enabling efficient representation of complex physically based rendering textures under varying illumination conditions. To the best of our knowledge, this is the first application of image synthesis specifically designed for planar artwork playback that combines novel view synthesis with photorealistic rendering to faithfully reproduce oil painting characteristics. We use a few SH coefficients (SH degree = 4) to approximate incident illumination and surface reflectance, reducing computational complexity while maintaining rendering fidelity. The system uses off-axis multiview photography with structured sampling (9×5 density) to capture the artwork's appearance from discrete viewpoints. A real-time tracking mechanism implemented with a depth camera dynamically determines the viewer's position and updates the viewing vector, enabling interactive perspective rendering. Experiments show that our approach achieves a negligible root-mean-square error (0.0015-0.0062) within the recommended viewing range. The simplified orthographic projection variant further improves computational efficiency, achieving 698.9 frames per second (FPS) on RTX 5090 and 30.4 FPS on embedded platforms. We demonstrate that SH-based image synthesis provides a cost-effective, scalable solution for photorealistic digital artwork presentation, bridging the gap between traditional art appreciation and interactive digital experiences.