DepthDiT

Diffusion Transformer for monocular depth estimation — adapting PixArt-Alpha and PixArt-Sigma for dense prediction

DepthDiT is a Diffusion Transformer architecture for monocular depth estimation, developed at the Vision and AI Lab, Indian Institute of Science (IISc) over 14 months.

Architecture

  • Adapted PixArt-Alpha and PixArt-Sigma Diffusion Transformer backbones for pixel-level depth prediction
  • Replaced the generation objective with a depth prediction head trained using diffusion loss
  • Designed a masked diffusion loss to better model mirror-like reflective surfaces, reducing artifacts in specular regions

Dataset

  • Built an automated pipeline to curate and QA 30,000 images from MatrixCity for depth training
  • Pipeline covered: scene filtering, depth validity checks, sampling diversity, and metadata tracking

Results

Metric Value
AbsRel 0.107
δ1 0.88
Steps 40k

Reflection Inpainting

Implemented DreamBooth and RealFill-inspired inpainting workflows to improve reflection coherence and consistency across generated scenes.

Venue: Vision and AI Lab, Indian Institute of Science (IISc), Bengaluru Duration: Jan 2024 – Feb 2025

Stack

Python · PyTorch · PixArt-Alpha · PixArt-Sigma · MatrixCity · DreamBooth · RealFill

Qualitative comparison against DepthAnything v2 and Lotus — DepthDiT (ours, right) on glass, netting, and specular surfaces.