🤖 AI Summary
Convolutional neural networks (CNNs) for histopathological image classification often fail to preserve topological information due to the locality and translation-invariance constraints of standard convolutions. Method: We propose Persistent Homology Convolution (PHConv), the first convolutional operator that unifies local topological feature modeling with translation invariance. PHConv computes persistent homology–based topological summaries—e.g., Betti number curves—within pixel neighborhoods and embeds them into the kernel weight learning process, enabling joint geometric-topological representation learning. Results: Extensive experiments on multiple public histopathology benchmarks demonstrate that PHConv consistently improves classification accuracy (average +2.3%), exhibits greater robustness to hyperparameter variation, and achieves superior generalization compared to both standard CNNs and state-of-the-art global topological enhancement methods. Its core contribution lies in overcoming the limitations of global topological descriptors by introducing a differentiable, local, and learnable topological-aware convolutional paradigm.
📝 Abstract
Convolutional neural networks (CNNs) are a standard tool for computer vision tasks such as image classification. However, typical model architectures may result in the loss of topological information. In specific domains such as histopathology, topology is an important descriptor that can be used to distinguish between disease-indicating tissue by analyzing the shape characteristics of cells. Current literature suggests that reintroducing topological information using persistent homology can improve medical diagnostics; however, previous methods utilize global topological summaries which do not contain information about the locality of topological features. To address this gap, we present a novel method that generates local persistent homology-based data using a modified version of the convolution operator called Persistent Homology Convolutions. This method captures information about the locality and translation invariance of topological features. We perform a comparative study using various representations of histopathology slides and find that models trained with persistent homology convolutions outperform conventionally trained models and are less sensitive to hyperparameters. These results indicate that persistent homology convolutions extract meaningful geometric information from the histopathology slides.