Looking in the mirror: A faithful counterfactual explanation method for interpreting deep image classification models
This addresses the need for more interpretable and intrinsic explanations in AI model debugging and trust, though it is an incremental improvement over existing counterfactual methods.
The paper tackled the problem of generating faithful counterfactual explanations for deep image classifiers by proposing Mirror-CFE, which operates directly in the classifier's feature space and achieved superior validity and input resemblance compared to state-of-the-art methods in experiments on four datasets.
Counterfactual explanations (CFE) for deep image classifiers aim to reveal how minimal input changes lead to different model decisions, providing critical insights for model interpretation and improvement. However, existing CFE methods often rely on additional image encoders and generative models to create plausible images, neglecting the classifier's own feature space and decision boundaries. As such, they do not explain the intrinsic feature space and decision boundaries learned by the classifier. To address this limitation, we propose Mirror-CFE, a novel method that generates faithful counterfactual explanations by operating directly in the classifier's feature space, treating decision boundaries as mirrors that ``reflect'' feature representations in the mirror. Mirror-CFE learns a mapping function from feature space to image space while preserving distance relationships, enabling smooth transitions between source images and their counterfactuals. Through extensive experiments on four image datasets, we demonstrate that Mirror-CFE achieves superior performance in validity while maintaining input resemblance compared to state-of-the-art explanation methods. Finally, mirror-CFE provides interpretable visualization of the classifier's decision process by generating step-wise transitions that reveal how features evolve as classification confidence changes.