IA-MVS: Instance-Focused Adaptive Depth Sampling for Multi-View Stereo
Yinzhe Wang, Yiwen Xiao, Hu Wang, Yiping Xu, Yan Tian
TL;DR
The paper tackles depth estimation in cascaded MVS by recognizing that individual instances occupy smaller depth ranges than whole scenes. It introduces Instance-Focused Adaptive Depth Sampling (IF-ADS) to re-sample depth hypotheses per instance, coupled with a filtering mechanism based on intra-instance depth continuity priors (FIIC) to improve robustness. A conditional probabilistic model-based confidence estimation (CPC) provides reliable, stage-aware confidence measures that reflect evolving depth-hypothesis spaces. When integrated with a transformer-based baseline (MVSFormer++) and optional SAM segmentation, IA-MVS achieves state-of-the-art results on the DTU dataset and demonstrates robust, training-free applicability to existing MVS frameworks. Overall, the approach offers practical, per-instance depth refinement and probabilistic confidence modeling to enhance depth maps and 3D reconstructions in real-world pipelines.
Abstract
Multi-view stereo (MVS) models based on progressive depth hypothesis narrowing have made remarkable advancements. However, existing methods haven't fully utilized the potential that the depth coverage of individual instances is smaller than that of the entire scene, which restricts further improvements in depth estimation precision. Moreover, inevitable deviations in the initial stage accumulate as the process advances. In this paper, we propose Instance-Adaptive MVS (IA-MVS). It enhances the precision of depth estimation by narrowing the depth hypothesis range and conducting refinement on each instance. Additionally, a filtering mechanism based on intra-instance depth continuity priors is incorporated to boost robustness. Furthermore, recognizing that existing confidence estimation can degrade IA-MVS performance on point clouds. We have developed a detailed mathematical model for confidence estimation based on conditional probability. The proposed method can be widely applied in models based on MVSNet without imposing extra training burdens. Our method achieves state-of-the-art performance on the DTU benchmark. The source code is available at https://github.com/KevinWang73106/IA-MVS.
