Probabilistic Deep Discriminant Analysis for Wind Blade Segmentation
Raül Pérez-Gonzalo, Andreas Espersen, Antonio Agudo
TL;DR
The paper tackles the limitation of linear discriminant analysis in non-linear segmentation tasks by introducing Deep Discriminant Analysis (DDA), which directly optimizes a Fisher-like criterion within deep networks. It stabilizes training through sigmoid-bounded outputs and a gradient-friendly reformulation, presenting two DDA losses— $\mathcal{L}_{DDA}^{(\\ln)}$ and $\\mathcal{L}_{DDA}^{(\\Delta)}$—and augmenting them with a probabilistic focal loss to form PDDA. Empirical evaluation on wind blade segmentation shows DDA substantially improves over LDA, while PDDA delivers state-of-the-art-like performance with high accuracy, F1, and mIoU and strong generalization across windfarms. The work demonstrates a data-efficient, robust segmentation approach suitable for wind-energy maintenance in constrained labeling scenarios.
Abstract
Linear discriminant analysis improves class separability but struggles with non-linearly separable data. To overcome this, we introduce Deep Discriminant Analysis (DDA), which directly optimizes the Fisher criterion utilizing deep networks. To ensure stable training and avoid computational instabilities, we incorporate signed between-class variance, bound outputs with a sigmoid function, and convert multiplicative relationships into additive ones. We present two stable DDA loss functions and augment them with a probability loss, resulting in Probabilistic DDA (PDDA). PDDA effectively minimizes class overlap in output distributions, producing highly confident predictions with reduced within-class variance. When applied to wind blade segmentation, PDDA showcases notable advances in performance and consistency, critical for wind energy maintenance. To our knowledge, this is the first application of DDA to image segmentation.
