Non-rigid registration based model-free 3D facial expression recognition
Autor: | Arman Savran, Bulent Sankur |
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Rok vydání: | 2017 |
Předmět: |
Computer science
business.industry Feature extraction Kanade–Lucas–Tomasi feature tracker 020207 software engineering Context (language use) 02 engineering and technology Dimension (vector space) Face (geometry) Signal Processing 0202 electrical engineering electronic engineering information engineering Feature (machine learning) 020201 artificial intelligence & image processing Computer vision Computer Vision and Pattern Recognition Artificial intelligence Representation (mathematics) business Software Independence (probability theory) |
Zdroj: | Computer Vision and Image Understanding. 162:146-165 |
ISSN: | 1077-3142 |
Popis: | We propose a novel feature extraction approach for 3D facial expression recognition by incorporating non-rigid registration in face-model-free analysis, which in turn makes feasible data-driven, i.e., feature-model-free recognition of expressions. The resulting simplicity of feature representation is due to the fact that facial information is adapted to the input faces via shape model-free dense registration, and this provides a dynamic feature extraction mechanism. This approach eliminates the necessity of complex feature representations as required in the case of static feature extraction methods, where the complexity arises from the necessity to model the local context; higher degree of complexity persists in deep feature hierarchies enabled by end-to-end learning on large-scale datasets. Face-model-free recognition implies independence from limitations and biases due to committed face models, bypassing complications of model fitting, and avoiding the burden of manual model construction. We show via information gain maps that non-rigid registration enables extraction of highly informative features, as it provides invariance to local-shifts due to physiognomy (subject invariance) and residual pose misalignments; in addition, it allows estimation of local correspondences of expressions. To maximize the recognition rate, we use the strategy of employing a rich but computationally manageable set of local correspondence structures, and to this effect we propose a framework to optimally select multiple registration references. Our features are re-sampled surface curvature values at individual coordinates which are chosen per expression-class and per reference pair. We show the superior performance of our novel dynamic feature extraction approach on three distinct recognition problems, namely, action unit detection, basic expression recognition, and emotion dimension recognition. |
Databáze: | OpenAIRE |
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