RESEARCH · COMPUTER VISION

Postgraduate research project · PPKE-ITK

Geometry-Guided Neural Compositing

A local, GPU-accelerated vision pipeline that reconstructs the 3D geometry of an ordinary single-camera video and inserts synthetic elements so they sit convincingly in the scene.

PyTorch · CUDA Local-first Reproducible License-clean

Capstone research project · Applied Artificial Intelligence postgraduate specialisation programme · Faculty of Information Technology and Bionics, Pázmány Péter Catholic University (PPKE-ITK)

Abstract

Making synthetic elements belong in real footage

Convincingly adding a synthetic element to existing video is hard.

10 neural models in the active pipeline
24 models evaluated & license-screened
0 non-commercial weights shipped
32-bit scene-referred linear working space

Capability map

Five vision problems, one coordinated system

Each domain is a substantial computer-vision problem in its own right.

01 1 model

Depth estimation

Temporally consistent per-pixel depth from a single moving camera.

02 2 models

Camera & scene solve

Recovering camera motion, intrinsics and sparse 3D structure.

03 1 model

Segmentation & occlusion

Video-consistent masks that decide what occludes what.

04 4 models

Generative synthesis

Diffusion-based image and motion generation, scene-conditioned.

05 2 models

Physically-based compositing

Shadows, matte, colour, grain and blur combined in linear light.

06 rule-based

Orchestration

A queue-backed worker system running reproducible, resumable jobs.

Under the hood

An intermediate view of the pipeline

A diagnostic representation from an intermediate stage — not the final composite.

intermediate · not final output

Engineering principles

The decisions that make it trustworthy

Beyond the models, the project is an exercise in disciplined systems engineering.

License-clean model stack

Only permissively-licensed weights (Apache-2.0 / MIT / BSD) ever enter the pipeline.

Reproducible by construction

Deterministic manifests record pinned model versions and fixed seeds.

VRAM-aware orchestration

Large models are hot-swapped in and out of VRAM to fit one consumer GPU.

Scene-referred linear compositing

All compositing happens in 32-bit float linear light; gamma only at the edges.

Non-destructive by default

The original footage and audio are preserved; the result is additive.

Local-first & private

Runs entirely on local hardware — no frames sent to any third-party API.

Technology

Stack

A GPU compute core in Python, wrapped in a typed job-orchestration layer.

PyTorch 2.x · CUDA 12.1 Python 3.11 OpenCV Open3D OpenEXR · 16-bit depth Diffusion models · SDXL-class TypeScript · worker orchestration Queue-backed jobs · resumable
Deliberately not shown

Scope of this page

This page presents the capabilities and engineering approach of the project.