Reply by authors
**We thank the reviewer for acknowledging our paper building connections between diffusion models and GANs, easy to follow, and containing extensive experiments.**
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**Q1: Not easy to collect paired image from SD.**
Paired data collection is not a hard issue. As mentioned in Sec. 3.1, diffusion models are used to generate edited images in the target domain, and the edited images and original images (e.g., images in the FFHQ dataset) naturally form paired data for GAN training.
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**Q2: About contribution to I2I community.**
As mentioned in Sec. 1 and Sec. 2, as diffusion models are too bulky and contain multiple sampling steps during inference, making them achieve real-time on-device inference is hard. Our paper mitigates this problem by bringing the image editing capability of diffusion models to lightweight and real-time GANs with distillation. To make the distillation process more efficient, we introduce a hybrid training pipeline that efficiently adapts a pre-trained text-conditioned GAN model to different concepts while substantially reducing computational and storage costs. We also reduce the amount of training data necessary to train each GAN.
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**Q3: About key contributions of the paper.**
Our main contribution is to build an efficient distillation pipeline (use fewer training efforts) that brings the image editing capability of diffusion models to an efficient GAN (achieves real-time inference on mobile). More specifically, our contributions include:
- We introduce a text-conditional base GAN model incorporating CONV layers with attention mechanisms. With this design, the base model can be trained on various prompts and the corresponding edited images obtained from diffusion models. Based on the base GAN model, a new editing concept only requires a fine-tuning process with reduced training costs compared to train-from-scratch setting.
- We identify partial crucial layers of the base GAN model, and further apply LoRA on the crucial layers with a simple and effective rank search process, instead of fine-tuning the entire base model. With this approach, we can greatly save the training and storage cost for a new concept.
- We reduce the amount of training data used to obtain a new concept based on similarity clustering.
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**Q4: About the task of transferring knowledge from SD to Pix2pix model. Is the approach generalizable for other tasks?**
Transferring knowledge from diffusion models to GANs has important advantages. Diffusion models are large in size and have high computation costs. Though recent works attempt to accelerate the image generation process of the diffusion models, the results are still far beyond real-time on-device inference, which is important for user experience. Our knowledge transferring pipeline can obtain GANs for new concepts in an efficient way, and allow real-time inference after deployment, which takes advantage of diffusion models but avoids the high storage cost and long latency issue.
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**Q5: About using attention mechanism.**
We acknowledge that attention mechanisms have been utilized in diffusion models, yet using it in GAN models is not that straightforward. Considering our objective is to achieve real-time inference on mobile while maintaining good image quality, the number and position of transformer blocks are important aspects to be investigated, as in Sec. 3.2.