Handling OOD Data in Synthetic Image Generation: A State-of-the-Art Review
Keywords:
anomaly detection, generative models, model evaluation, synthetic image generation, out-of-Abstract
Synthetic image generation through generative models (GANs, diffusion models) has seen remarkable progress, but the identification and handling of out-of-distribution (OOD) data remains a critical challenge for the reliable deployment of these models. This review examines the state of the art in OOD detection within the context of synthetic image generation. Widely used generative architectures such as Wasserstein GAN with gradient penalty (WGAN-GP) and StyleGAN2-ADA are analyzed, along with evaluation metrics like Fréchet Inception Distance (FID). Furthermore, recent strategies that enhance OOD discrimination without requiring OOD data during training are reviewed, such as SeTAR (which selectively adjusts internal representations) and ABET (which combines energy and learned temperature scaling). The literature synthesis indicates that integrating OOD detection techniques into generative models not only increases the models' ability to distinguish between in-distribution and out-of-distribution examples but also promotes greater visual fidelity and stability in synthetic images, especially in scenarios with limited or critical real data. The review concludes by identifying gaps in knowledge and proposing future research directions to strengthen the applicability of these models in sensitive domains.
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