View-structured conformal prediction improves 3d gaussian splatting reliability

View-Structured Conformal Prediction for 3D Gaussian Splatting

Machine LearningComputer Vision and Pattern Recognition

Summary

Rendering new 3D views quickly can be uncertain, and it's hard to know how accurate these images are pixel by pixel. The authors treat generating new views as a prediction problem and propose a method called View-Structured Conformal Prediction (VSCP) to give reliable guarantees about the accuracy of these images across different views. VSCP adjusts the confidence scale based on the difficulty of each view, leading to better and tighter uncertainty estimates. Tested on real scenes, their method shows improved coverage and efficiency compared to previous approaches.

What this means in practice

Authors

Junzheng Chu, Bin Pan, Zhenwei Shi

Abstract

3D Gaussian Splatting (3DGS) renders novel views in real time, but an uncertainty heatmap does not certify that a rendered view meets a certain prediction coverage. We treat novel-view synthesis as structured regression and ask that, with probability at least $1-α$, RGB prediction boxes cover at least a $1-β$ fraction of pixels in a new view. We propose View-Structured Conformal Prediction (VSCP). It splits the pre-calibration scale into a spatial shape from the renderer and a transferable view-difficulty factor, which predicts the smallest view-wise multiplier that shape needs. A held-out quantile over views (View-CP) then gives finite-sample validity even when transferring to new scenes. The same factorization makes the analysis exact: a conformity score is the ratio of oracle to predicted view difficulty, and excess width separates into a test-side and a calibration-side term. Across 13 real scenes, pixel-pooled calibration reaches 89.9\% marginal pixel coverage but only 61.4\% view-event coverage at a 90\% target, while View-CP reaches 91.7--92.0\%. At matched coverage VSCP cuts width by 22.1\% against a constant scale, and matches a ten-model ensemble's 21.0\% reduction using only one model per scene and four rather than ten rasterization passes per query. VSCP also improves on the closest single-model baseline, the 3DGS-U field, by 4.7 points ($p=0.0225$). The view predictor transfers from bounded source families to all nine unbounded Mip-NeRF~360 scenes. There the full scale beats the constant scale with 20.7\% width saving on all nine scenes. It also keeps an 18.3\% saving under a different densification backbone and runs at 216--280 FPS on an RTX~4090.