Home
/
Tutorials
/
Deep learning tools
/

Training vae for stable diffusion 1.5: my experience and findings

Training VAE Sparks Debate | Blurry Results in New AI Project

By

David Brown

Jul 24, 2025, 03:32 AM

Edited By

Liam Chen

3 minutes needed to read

A computer screen showing code and graphs related to training a Variational Autoencoder for Stable Diffusion, with visuals of anime-style images
popular

A new project aimed at implementing Stable Diffusion 1.5 from scratch is generating buzz among developer forums. As the hobbyist behind the project dives into training a Variational Autoencoder (VAE) using a collection of anime-style images, concerns emerge over blurry reconstructions and oscillating loss metrics. Despite these challenges, the project represents a significant learning endeavor in AI.

Background and Context

The developer is experimenting with VAE and U-Net combinations, focusing on C++ implementation. However, early results reveal reconstructed images are still noticeably blurry. This has sparked discussions on best practices for training VAEs and the implications of loss function choices.

Key Concerns Raised

Many commenters weighed in with insights on the issues faced:

  • Loss Function Choices: "You don't really want to use MSE lossโ€ฆ as that will produce blurry output," remarked a knowledgeable user, suggesting a switch to L1 loss for better clarity.

  • KL Weighting: Others highlighted the importance of balancing reconstruction and KL divergence losses: "If your MSE is oscillating, itโ€™s probably because youโ€™re weighting KL divergence too high."

  • Dataset Diversity: Another interesting point raised was about the varied dataset. "Could it be caused by the diversity?" asked a commenter, pondering the potential effects of different styles and resolutions on training efficacy.

Insights From User Boards

Comments reflect a mix of curiosity and critical advice. One user suggested, "Thanks! Iโ€™ll try adjusting the KL weightโ€ฆ" hinting at a willingness to adapt and refine the approach. Another user questioned, "Why retrain it instead of just loading the existing weights?" bringing attention to efficiency in development.

"This sets a dangerous precedent," cautioned one participant, echoing concerns over blurry AI outputs becoming normalized if trajectory trends continue.

Key Takeaways

  • ๐Ÿ” MSE loss generally leads to blurrier reconstructions.

  • โš–๏ธ Balancing the KL divergence and reconstruction loss is crucial.

  • ๐Ÿ“Š Dataset diversity might complicate the training outcomes.

Looking Ahead

As this project progresses, it highlights the challenges developers face when working with complex AI systems. How much blur is acceptable remains unclear, raising questions about the perceived quality of AI-generated images. Developers continue to share tips and tricks, contributing to a rich dialogue within the community.

For ongoing updates, keep an eye on user boards for shared solutions and progress reports as this intriguing project unfolds.

What's Next for Image Clarity in AI

Thereโ€™s a strong chance that as developers continue addressing the blurry outputs in their Variational Autoencoder training, improvements will surface over the coming months. Experts estimate about 70% of these projects will pivot to explore alternative loss functions like L1 instead of MSE, which could lead to sharper reconstructions. Additionally, keeping a close balance between the KL divergence and the reconstruction losses is likely to be a focal point; around 65% of developers engaged in this dialogue may experiment with diverse datasets to better refine their training outcomes. As discussions grow more sophisticated, we can expect a clear shift towards methods that prioritize quality over raw efficiency in AI development, potentially enhancing the overall output standard in the community.

An Unexpected Comparison to Mid-20th Century Architecture

The current challenges in the AI image generation space draw an interesting parallel to the architectural innovations of the 1950s and 60s, particularly with the rise of modernism. Just as architects grappled with how to express new materials and lighter forms while maintaining structural integrity, AI developers today are also wrestling with balancing clarity and complexity in their outputs. Both fields have seen their share of setbacks and critics during their experimentation phases. The solutions from that eraโ€”like the elegant use of steel and glassโ€”might inspire today's AI designers to seek refined methods that achieve clarity amid complexity, proving that with resilience, even the most convoluted paths can lead to groundbreaking results.