An Overview of Diffusion Model-Based Image Editing: Methodologies and Future Directions
The rapid advancements in denoising diffusion models have paved the way for significant developments in the field of image editing, a crucial subdomain in AI-generated content (AIGC). The paper "Diffusion Model-Based Image Editing: A Survey" presents a comprehensive examination of the role diffusion models play in enabling complex image editing tasks. The paper not only categorizes existing methodologies but also addresses the challenges and potential future advancements in this vibrant research domain.
The authors classify diffusion model-based image editing methods into three prominent categories based on their learning strategies: training-based approaches, testing-time finetuning, and models that are both training and finetuning free. Training-based approaches are further subdivided into domain-specific editing methods that utilize CLIP guidance, cycling regularization, projection and interpolation, and classifier guidance to enhance model capabilities in specific domains. These methods are particularly beneficial for tasks such as semantic and stylistic editing, where generating nuanced artistic styles or performing unpaired image-to-image translations is required.
Testing-time finetuning methods offer precise control over image edits by finetuning specific layers or embeddings of a model. Approaches like denoising model finetuning, embedding adjustment, latent variable optimization, and hybrid finetuning highlight the scope of achieving fine-grained edits with minimal computational overhead, making them suitable for real-time applications.
In contrast, training and finetuning free methods leverage the inherent principles of diffusion models, focusing on techniques such as formulating user prompts, modifying inversion and sampling processes, or employing mask-guided techniques to achieve desired image alterations without retraining the model. These methods highlight the versatility and usability of diffusion models in practical settings.
The paper places significant emphasis on the tasks of image inpainting and outpainting, aligning traditional context-driven methods with contemporary multimodal conditional approaches that utilize text, segmentation maps, or reference images for guidance. The latter methods, particularly, illustrate how pretrained diffusion models can be fine-tuned to address complex tasks with enhanced precision, underscoring the models' adaptability.
Evaluation of these methodologies is supported by EditEval, a benchmark introduced in the paper for assessing diffusion-based image editing. It features LMM Score, an innovative metric designed to quantify editing performance across tasks, reinforcing the importance of standardized evaluations to advance field research.
Despite recent progress, the field faces several challenges, such as the need for fewer-step model inference, efficient model architectures, and the ability to handle complex object structures, lighting, and shadows. Robustness remains an ongoing concern, with methods often struggling to maintain consistency across diverse scenarios. The authors advocate for developing metrics beyond traditional user studies, suggesting directions involving large multimodal models for more comprehensive evaluations.
In conclusion, the survey highlights the substantial potential and transformative impact of diffusion models in image editing. By offering a detailed exploration of the existing methodologies and pinpointing areas necessitating further research, it sets the stage for future advancements that promise to enhance the fidelity and versatility of image editing technologies in the AIGC domain.