HDR Panorama Lighting Prediction Using Synthetic Portrait Data

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Solution Overview

Problem

Existing lighting estimation deep learning models are biased towards certain demographic groups due to the high cost and time required for collecting paired portrait image and HDR environment map datasets, limiting their ability to cover diverse environments and subjects.

Innovation Solution

A deep learning model trained on a synthetic dataset of diverse subjects and environments, using a generator and discriminator architecture with specific loss functions, to predict HDR environment panoramas from LDR limited field-of-view portrait images.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If real paired portrait image and HDR environment map datasets are collected for training, then model training accuracy is improved, but cost and time consumption increase significantly

Engineering Contradiction:
Improvelighting estimation accuracyVSAvoiddata collection time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent uses synthetic portrait images generated from 3D face models as copies of real portraits, paired with corresponding HDR environment maps. This copying approach allows training without expensive real-world data collection, while maintaining the structural relationships needed for accurate lighting estimation.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The patent extracts only the essential lighting and geometric information needed for training by using simplified 3D face models and synthetic rendering, separating the critical training elements from the complexity of real-world data collection.

Inventive Principle:
Principle #2Taking out (Extraction)

2Measurement precision

If real paired portrait image and HDR environment map datasets are collected for training, then model training accuracy is improved, but cost increases significantly

Engineering Contradiction:
Improvelighting estimation accuracyVSAvoiddata collection ease
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent creates synthetic training data by rendering 3D face models under controlled lighting conditions, copying the essential visual and lighting properties without the logistical burden of real-world data collection.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The synthetic data generation process is self-contained, using automated rendering pipelines that generate paired images and environment maps without requiring human subjects, equipment, or coordination.

Inventive Principle:
Principle #25Self-service

3Productivity

If small real datasets are used for training, then training cost and time are reduced, but model bias towards certain demographic groups increases

Engineering Contradiction:
Improvetraining efficiencyVSAvoiddemographic coverage
Core Design Contradiction:
ProductivityVSAdaptability or versatility

Solution Approach 1:

The patent varies parameters of the 3D face models including ethnicity, age, gender, and facial features to generate diverse synthetic portraits. This parameter variation ensures broad demographic coverage while maintaining efficient automated training.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The synthetic data generation system serves multiple functions: it creates diverse demographic representations, ensures consistent lighting-ground truth pairings, and enables scalable dataset generation across different population groups.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentUS20250209670A1Deep learning systems, devices, and methods for predicting high-dynamic range environment panoramas
Publication Date: 2025.06.26 LOREAL SA
  • US20250209670A1 patent drawing
  • US20250209670A1 patent drawing
  • US20250209670A1 patent drawing

AI summary

Aspects of lighting estimation, and models therefor are provided including aspects to train such models. There is provided a lighting estimation model pre-trained using synthetic data to alleviate the costs and difficulty in obtaining real portrait image and HDR environment map paired datasets. To improve model performance, the model is training utilizing a discriminator configured to predict one or more average color values of a defined percentage of highest intensity pixels of a predicted environment map and to determine a color loss associated with the predicted environment map and the one or more average color values. The trained model can be used for a wide range of downstream tasks, including being used to generate hair renderings with realistic lighting effects for virtual try on experiences.