Measuring Domain Shifts in Remote Photoplethysmography using Deep Learning Model Similarity
מושגי ליבה
Domain shift differences between training data and deployment context can severely impact the performance of deep learning models. We propose metrics based on model similarity to measure domain shifts, demonstrating high correlation with empirical performance.
תקציר
The authors investigate the domain shift problem in the context of remote photoplethysmography (rPPG), a technique for video-based heart rate inference. They propose three metrics based on Centered Kernel Alignment (CKA) to measure the domain shift between datasets:
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Dataset-based CKA Difference (DS-diff): Compares the self-similarity of a model across two datasets, with a larger difference indicating a more severe domain shift.
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Dataset-based CKA Similarity (DS-sim): Compares a model's behavior across two datasets, with higher similarity indicating a less severe domain shift.
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Model-based CKA Similarity (Model-sim): Compares the similarity of two models trained on different datasets, with higher similarity indicating a less severe domain shift.
The authors conduct experiments across 21 datasets and demonstrate that DS-diff and Model-sim exhibit high correlation with empirical performance, as measured by mean absolute error (MAE) in heart rate estimation. They also apply DS-diff to a model selection problem, where ground truth for the evaluation domain is unknown, and show a 13.9% performance improvement over the average case baseline.
Measuring Domain Shifts using Deep Learning Remote Photoplethysmography Model Similarity
סטטיסטיקה
The authors report the following key statistics for the datasets used in the experiments:
Time duration ranging from 15 seconds to over 10 minutes
Average heart rates ranging from under 70 beats per minute (BPM) to over 100 BPM
Heart rate standard deviations ranging from under 3 BPM to over 8 BPM
These statistics suggest significant differences in the datasets, which can contribute to domain shifts.
ציטוטים
"Domain shift differences between training data for deep learning models and the deployment context can result in severe performance issues for models which fail to generalize."
"As an example from a different application, in [10] significant racial bias was found in the form of a performance gap between white and black users of machine learning based automated speech recognition (ASR) services deployed by major companies."
"Building on the findings from [24], we investigated the use of Centered Kernel Alignment (CKA) as a tool for the measurement of domain shifts."
שאלות מעמיקות
How can the proposed domain shift metrics be extended to other computer vision tasks beyond remote photoplethysmography
The proposed domain shift metrics based on model similarity can be extended to other computer vision tasks beyond remote photoplethysmography by adapting the methodology to different datasets and models. The key idea is to analyze the similarity of model activations between different datasets to measure the domain shift. This approach can be applied to various computer vision tasks by training models on different datasets and evaluating their performance on unseen data. By calculating metrics such as DS-diff and Model-sim for these tasks, researchers can assess the domain shift and make informed decisions about model generalization.
What are the potential limitations of using model similarity as a proxy for domain shift, and how can these be addressed
One potential limitation of using model similarity as a proxy for domain shift is that it may not always directly correlate with empirical performance. While model similarity metrics like DS-diff and Model-sim can provide insights into how datasets differ in terms of model activations, these differences may not always translate to actual performance on unseen data. To address this limitation, researchers can combine model similarity metrics with other domain adaptation techniques, such as adversarial learning or unsupervised adaptive learning, to improve model generalization. Additionally, conducting thorough empirical evaluations and validation on diverse datasets can help validate the effectiveness of model similarity metrics in predicting domain shift.
How can the insights from this work on domain shift measurement be leveraged to develop more robust and generalizable deep learning models for real-world applications
The insights from this work on domain shift measurement can be leveraged to develop more robust and generalizable deep learning models for real-world applications by incorporating domain shift analysis into the model development pipeline. By systematically evaluating domain shifts using metrics like DS-diff and Model-sim during model training and selection, researchers can identify potential performance bottlenecks and fine-tune models to improve generalization. Furthermore, understanding the impact of domain shifts on model performance can guide the collection of diverse and representative datasets, leading to more robust models that can adapt to different deployment contexts. Overall, integrating domain shift analysis into the model development process can enhance the reliability and effectiveness of deep learning models in real-world applications.
