Bridging the Domain Gap in Heterogeneous Face Recognition through Conditional Adaptive Instance Modulation

Core Concepts

The core message of this paper is that the domain gap in Heterogeneous Face Recognition (HFR) can be effectively addressed by conceptualizing different modalities as distinct styles and employing a Conditional Adaptive Instance Modulation (CAIM) module to seamlessly adapt the intermediate feature maps of a pre-trained face recognition network.

Abstract

The paper proposes a novel approach to address the domain gap in Heterogeneous Face Recognition (HFR) by treating different modalities as distinct styles. The key contributions are:

Conceptualizing the domain gap in HFR as a manifestation of distinct styles from different imaging modalities, and addressing this as a style modulation problem.

Introducing a new trainable component called Conditional Adaptive Instance Modulation (CAIM) that can transform a pre-trained face recognition network into an HFR-ready system, requiring only a limited number of paired samples for training.

Evaluating the proposed CAIM approach on various challenging HFR benchmarks, including VIS-Thermal, VIS-Sketch, VIS-NIR, and VIS-Low Resolution, demonstrating its effectiveness in outperforming state-of-the-art methods.

Conducting extensive ablation studies to understand the impact of different components of the CAIM module and the optimal number of layers to adapt.

The CAIM module seamlessly integrates into the pre-trained face recognition network, modulating the intermediate feature maps to align the embeddings of the target modality with the source modality. This approach eliminates the need for computationally expensive image synthesis, which is a common strategy in previous HFR methods.

Stats

The domain gap between different modalities can lead to a significant drop in performance when face recognition networks trained on visible-light images are applied to images from different sensing modalities.
Collecting large-scale paired datasets for additional modalities is challenging and can incur significant costs.

Quotes

"Heterogeneous Face Recognition (HFR) systems are designed to facilitate cross-domain matching, enabling the comparison of enrolled RGB images with NIR (or other types of) images without necessitating the enrollment of separate modalities."
"We conceptualize the domain gap in Heterogeneous Face Recognition (HFR) as a manifestation of distinct styles from different imaging modalities, and address this domain gap as a style modulation problem."

Key Insights Distilled From

From Modalities to Styles: Rethinking the Domain Gap in Heterogeneous Face Recognition

by Anjith Georg... at arxiv.org 04-23-2024

https://arxiv.org/pdf/2404.14247.pdf

Deeper Inquiries

How can the CAIM module be further extended to handle a larger number of modalities without significantly increasing the computational overhead?

The CAIM module can be extended to handle a larger number of modalities by implementing a more efficient gating mechanism. Instead of having a binary gate that activates the module for the target modality, a multi-level gating mechanism can be introduced. This multi-level gating system can dynamically adjust the level of modulation based on the specific characteristics of each modality. By incorporating adaptive gating, the CAIM module can selectively modulate the feature maps according to the requirements of each modality, reducing the computational overhead associated with unnecessary modulation.
Additionally, the CAIM module can be optimized to share parameters across different modalities where possible. By identifying commonalities in the style variations across modalities, shared parameters can be utilized to reduce the overall number of parameters in the network. This parameter sharing strategy can help in handling a larger number of modalities without significantly increasing the computational complexity.

What are the potential limitations of the style modulation approach, and how can it be improved to handle more complex domain shifts?

One potential limitation of the style modulation approach is its reliance on the assumption that the domain gap can be effectively addressed by modulating the feature maps to align with different styles. However, in cases of more complex domain shifts where the variations between modalities are not solely related to style differences, the style modulation approach may not be sufficient.
To improve the handling of more complex domain shifts, the style modulation approach can be enhanced by incorporating domain-specific adaptation mechanisms. This can involve integrating domain adaptation techniques that focus on learning domain-invariant features or leveraging adversarial training to align feature distributions across modalities. By combining style modulation with domain adaptation strategies, the approach can better capture the underlying domain shifts and improve the model's robustness to diverse modalities.
Furthermore, introducing more sophisticated feature alignment methods, such as domain-specific normalization layers or domain-specific attention mechanisms, can enhance the model's ability to handle complex domain shifts. By incorporating these advanced techniques into the style modulation framework, the approach can be better equipped to address the challenges posed by more intricate domain variations.

Could the CAIM framework be applied to other computer vision tasks beyond face recognition, such as object detection or segmentation, to address domain adaptation challenges?

Yes, the CAIM framework can be extended to other computer vision tasks beyond face recognition to address domain adaptation challenges in tasks such as object detection or segmentation. The core concept of modulating feature maps to align with different styles can be applied to various computer vision tasks where domain shifts exist.
For object detection, the CAIM framework can be integrated into the backbone networks of object detection models to adapt to different imaging modalities. By modulating the intermediate feature maps based on the specific characteristics of each modality, the model can improve its performance in detecting objects across diverse domains.
Similarly, in image segmentation tasks, the CAIM module can be incorporated into the segmentation networks to handle domain shifts between different modalities. By adjusting the feature representations to align with the style variations in each modality, the segmentation model can better generalize to unseen domains and improve segmentation accuracy.
Overall, the CAIM framework's style modulation approach can be a versatile tool for addressing domain adaptation challenges in various computer vision tasks beyond face recognition, providing a flexible and effective solution for handling diverse modalities and domain shifts.