Colab x Diffusers Tutorial: LoRAs, Image to Image, Sampler, etc - Stable Diffusion in Colab

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15 Jan 202417:41

TLDRThis tutorial video guides viewers through advanced features of using Stable Diffusion in Colab for image generation. It starts by setting up a Colab notebook, installing necessary packages, and demonstrates text-to-image generation with customizable parameters like height, width, sampling steps, and guidance scale. The tutorial then explores adding LoRAs (Low-Rank Adaptations) to modify the generated images, changing the sampler for a balance between speed and quality, and adjusting the number of images output per prompt. Additionally, it covers image-to-image functionality, where an existing image is used as a base to create a new image with specific modifications. The video concludes with tips on how to upload images from a URL or a local computer for image-to-image processing. The presenter also emphasizes the importance of reading documentation for self-learning and customization.


  • 📚 First, create a Colab notebook and install necessary packages and dependencies for using Stable Diffusion.
  • 🔗 Connect to a T4 GPU runtime in Colab for better performance.
  • 📝 Install packages by running the first cell of the notebook, which is essential for newcomers to Colab.
  • 🧩 Add LoRAs (Low-Rank Adaptations) to the text-to-image process by using the `load_Lora_weights` function and specifying the path to the Lora.
  • 🌟 Find Lora checkpoints on platforms like Civit AI and upload them to Hugging Face to use in your notebook.
  • ⚙️ Adjust the importance of the Lora in the image generation by setting the `cross_attention_kwargs` parameter.
  • 🎨 Change the sampler used in the diffusion process for a balance between speed and quality, like DPM++ or SD-Caris.
  • 🖼️ Modify the number of images output per prompt by changing the `num_images` parameter in the pipeline.
  • 🖌️ For image-to-image tasks, use the `image_to_image_pipeline` and provide an initial image along with the prompt.
  • 🔄 Use the `noising_strength` parameter to control how much of the base image is followed in the image-to-image generation.
  • 📈 Optimize code efficiency by separating blocks based on their function to avoid reloading the checkpoint every time.
  • 🌐 Utilize online tools like for easy generation of high-quality, realistic images without complex settings.

Q & A

  • What is the main focus of the video tutorial?

    -The video tutorial focuses on how to use Stable Diffusion in Colab for various image generation tasks, including adding LoRAs (Low-Rank Adaptations), changing the sampler, performing image-to-image transformations, and outputting multiple images based on a single prompt.

  • What is a LoRA and how is it used in the context of Stable Diffusion?

    -LoRA stands for Low-Rank Adaptation. It is a technique used to modify a pre-trained model with a smaller model that adjusts specific aspects of the original model's output. In the context of Stable Diffusion, LoRAs can be used to add specific styles or features to the generated images, such as a particular celebrity's likeness.

  • How does one change the sampler in the Stable Diffusion pipeline?

    -To change the sampler in the Stable Diffusion pipeline, one needs to import the desired scheduler from the diffusers library and replace the default scheduler with the chosen one in the pipeline code. DPM-Solver Multistep Scheduler is mentioned as a good balance between speed and quality.

  • What is the purpose of the 'number of images per prompt' parameter?

    -The 'number of images per prompt' parameter allows users to specify how many different images they want to generate from a single text prompt. This can be useful for getting a variety of outputs from a single input description.

  • How can one upload an image from their computer for image-to-image transformation?

    -To upload an image from the computer for image-to-image transformation, one can save the image on their computer, then drag and drop it into the Colab notebook's file upload section. After uploading, the image path is used to set the initial image for the image-to-image pipeline.

  • What is the significance of the 'noising strength' parameter in image-to-image transformations?

    -The 'noising strength' parameter determines how much of the base image's details are retained in the transformed image. A higher value will result in a more abstract transformation, while a lower value will keep the new image closer to the original.

  • How does one use an image from a URL for the base image in image-to-image transformations?

    -To use an image from a URL, one can simply paste the image URL into the code where the base image is defined. The image will then be downloaded and used as the base for the transformation.

  • What is the role of the 'cross_attention_kwargs' parameter when adding a LoRA to the pipeline?

    -The 'cross_attention_kwargs' parameter is used to adjust the merging ratio of the LoRA, which essentially controls the influence of the LoRA on the final image. It allows users to fine-tune how much of the LoRA's effects are applied.

  • Why is it recommended to separate the code that loads the checkpoint?

    -Separating the code that loads the checkpoint is recommended to improve efficiency. Loading the checkpoint can be a time-consuming process, so by separating it, the notebook doesn't need to reload the checkpoint every time it runs, which speeds up subsequent image generation.

  • How can one ensure that the generated images are not flagged as NSFW by the safety checker?

    -To prevent the generated images from being flagged as NSFW (Not Safe For Work), the safety checker can be set to 'none' in the pipeline configuration. This allows the generation of a wider range of images without the risk of getting a blank image due to a safety check failure.

  • What is the benefit of using the Hugging Face platform to store and access LoRAs?

    -The Hugging Face platform provides a convenient way to store, share, and access LoRAs. By uploading a LoRA to Hugging Face, users can easily access it from different projects and environments, such as a Colab notebook, without having to manually manage the file paths or storage.



📚 Introduction to Stable Diffusion 2

The video begins by introducing the continuation of a previous tutorial, where the focus is on expanding the capabilities of a 'collab notebook'. The host guides viewers on how to install necessary packages and dependencies, and demonstrates the process of creating a text-to-image using stable diffusion. The video covers advanced features such as adding LoRAs (Low-Rank Adaptations), changing the sampler, image-to-image transformations, and outputting multiple images.


🔍 Adding LoRAs to the Stable Diffusion Pipeline

The host explains how to integrate LoRAs into the text-to-image process to customize the generated images further. The process involves uploading a LoRA to Hugging Face, setting a variable for the LoRA path, and adjusting the merging ratio of the LoRA using the 'cross_attention_kwargs' parameter. The video provides a step-by-step guide on how to find and use LoRAs, specifically using 'The Rock' as an example, and emphasizes the importance of trigger words in the prompt to activate the LoRA.


🎨 Customizing the Sampling Method and Output

The video moves on to discuss changing the sampling method to DPM Plus++ 2M Car, which offers a balance between speed and quality. The host shows how to add different sampling methods or schedulers to the code. After that, the video covers how to output more than one image per prompt by adjusting the 'num_images' parameter. The host also shares a code snippet for displaying all images in the output list and briefly touches on the sponsorship by upix, a tool for generating high-quality images.


🖼️ Image-to-Image Processing and Documentation Utilization

The final part of the video addresses image-to-image processing. The host demonstrates how to use the 'image-to-image' pipeline, which allows users to transform an existing image based on a text prompt. The process includes uploading an image, setting the 'initial image' variable, and adjusting the 'noising strength'. The video also emphasizes the importance of reading and understanding documentation to solve coding issues. The host shares the notebooks for both text-to-image and image-to-image processes and encourages viewers to explore the diffusers documentation for a deeper understanding.




Colab, short for Google Colaboratory, is an online platform that allows users to write and execute Python code in their browser, with the added benefit of free access to computing resources, including GPUs. In the video, it is used as the environment to create and run a notebook for generating images using Stable Diffusion.


Diffusers is a Python library that provides tools for generative models, particularly for diffusion models which are a type of deep learning model used in generative tasks such as image synthesis. The video script discusses using Diffusers for text-to-image generation and image-to-image translation.

💡Stable Diffusion

Stable Diffusion is a model within the Diffusers library designed for generating images from textual descriptions. It is highlighted in the video as the primary tool for creating images, with various customizations such as LoRAs, samplers, and image-to-image functionality.

💡LoRAs (Low-Rank Adaptations)

LoRAs are a technique used to adapt pre-trained models to new tasks by altering only a small portion of the model's weights. In the context of the video, LoRAs are used to modify the Stable Diffusion model to generate images in the style of a specific subject, such as 'The Rock'.

💡Image to Image

Image to image refers to a process where an existing image is used as a base to generate a new image, often with modifications or enhancements. The video demonstrates how to use the Stable Diffusion model to perform image-to-image translation, allowing users to create new images based on existing ones.


In the context of generative models, a sampler is an algorithm that determines how the model generates new data points. The video discusses changing the sampler to DPM-Solver Multistep Scheduler, which is said to offer a good balance between speed and quality in image generation.


Text-to-image is a process where a model generates images based on textual descriptions. It is a core topic of the video, where the host explains how to use Stable Diffusion to generate images from text prompts, including adding customizations like LoRAs.

💡Hugging Face

Hugging Face is a company that provides a platform for machine learning models, including natural language processing and computer vision models. In the video, it is used to host and access the LoRA model for 'The Rock', which is then used in the image generation process.

💡Civit AI

Civit AI is mentioned as a good place to look for LoRAs and checkpoints, which are pre-trained models or states that can be used to continue training or to adapt models to new tasks. It is part of the process of customizing the Stable Diffusion model in the video.

💡Noising Strength

Noising strength is a parameter in image-to-image translation that determines how much of the base image's content is retained in the generated image. The video shows how to adjust this parameter to control the degree of change from the original image.

💡Multiple Image Outputs

The ability to output multiple images from a single prompt or base image is a feature discussed in the video. It is achieved by setting the 'number of images per prompt' parameter, allowing users to generate a series of images from the same input.


The video is a continuation of a previous tutorial on creating a Colab notebook for text-to-image using Stable Diffusion.

The tutorial demonstrates how to add LoRAs (Low-Rank Adaptations) to the text-to-image process.

Instructions on changing the sampler to DPM Plus++ for a balance between speed and quality.

The process of uploading a LoRA model to Hugging Face and integrating it into the Colab notebook.

How to adjust the LoRA weight to control the influence of the LoRA on the generated image.

The use of specific trigger words in the prompt to activate the LoRA effect.

Optimization tips for separating code blocks to avoid reloading the checkpoint every time.

A method to generate multiple images per prompt by adjusting the 'number of images per prompt' parameter.

Displaying all generated images using a loop to iterate through the image list.

The capability to perform image-to-image generation using the Stable Diffusion pipeline.

How to input an image for image-to-image generation either from a URL or by uploading it to Colab.

Adjusting the noising strength parameter to control how closely the new image follows the base image.

The importance of maintaining the same aspect ratio for the output image as the base image.

Tips on how to read and analyze documentation to solve specific problems in coding.

The video provides two separate Colab notebooks for text-to-image and image-to-image generation.

A recommendation to go through the diffusers documentation for a deeper understanding and self-learning.

The presentation of a site where one can search for all AI tools, called ai-search.