PXDepth: Pixel-Space Modeling for Structure Preserving Monocular Depth Estimation

1Sun Yat-sen University 2Shenzhen-FNii 3CUHKSZ

*Corresponding author

Paper Code Demo Coming soon

TL;DR: PXDepth separates global context encoding from pixel-space depth prediction, using a Global Context Encoder and a Pixel-Space Depth Predictor.

Qualitative Visualization

Interactive point clouds
PXDepth Ours
Loads when this section is visible
Baseline
Loads when this section is visible
Rotate left drag Zoom wheel or pinch Pan right drag or Shift-drag Focus double click Adjust align one view, then Done Reset R or button
Choose a scene Street II 11 / 14
Hover for a larger RGB preview

Overview

PXDepth teaser comparing indoor, outdoor, and wild-scene point clouds alongside global accuracy, boundary CD, and latency results.

Comparison To Existing Architecture

Comparison of convolutional decoding, multi-step diffusion decoding, and PXDepth pixel-space prediction.
(a) Discriminative Architecture (b) PPD (c) Ours

Discriminative models. A large-patch ViT captures global context, while a convolutional decoder upsamples its low-resolution features in a single feed-forward pass. This is efficient, but coarse tokenization weakens high-frequency cues that upsampling may not fully recover, leading to distorted local structures.

PPD. Pixel-space diffusion, semantic guidance, and a cascaded DiT preserve high-frequency information and improve fine structures. However, multi-step denoising repeatedly evaluates the network, resulting in high latency.

PXDepth. A Global Context Encoder supplies scene-level geometry, while a CM-PiT-based Pixel-Space Depth Predictor maintains pixel-space features with coarse-to-fine compaction. This single-pass design preserves local structure while maintaining low latency.

Qualitative Comparison

Qualitative point-cloud comparison between MoGe-2, MDA, PPD, InfiniDepth, and PXDepth across indoor and outdoor scenes.
Image MoGe-2 MDA PPD InfiniDepth Ours

Quantitative Comparison

Category Method MoGe Benchmark MDA Benchmark Latency ↓
Rel ↓ δ₁ ↑ Rel ↓ δ₁ ↑ Boundary CD ↓
Global
Prediction
DA V2 8.0 93.0 4.7 96.5 112.8 55.3
DepthPro 6.7 93.6 3.9 97.0 106.4 206.8
MoGe-2 5.1 95.6 3.5 96.9 100.3 32.9
Structure
Aware
InfiniDepth 7.2 94.1 4.7 96.7 98.9 65.7
PPD 7.5 92.6 4.4 96.5 93.7 209.8
MDA 8.2 90.5 3.6 96.7 72.8 267.1
PXDepth 5.8 94.8 3.6 97.0 70.6 56.4

Rel and δ₁ measure global depth accuracy, while Boundary CD measures boundary sharpness. Boundary CD is reported in millimeters (mm). Latency is measured per image at 518 × 518 on an RTX 5880 GPU and reported in milliseconds (ms).

BibTeX

Coming soon