ComfyUI Node: DiffuseHighSampler

DiffuseHighSampler:

The DiffuseHighSampler is a specialized node designed to facilitate the generation of images at resolutions higher than those for which the model was originally trained. This node is particularly beneficial for AI artists looking to upscale their creations without losing the intricate details and quality inherent in the original model's output. By leveraging advanced sampling techniques, the DiffuseHighSampler allows for seamless integration with other sampler nodes, such as SamplerCustom, to enhance the resolution of images while maintaining the artistic intent. Its primary function is to manage the diffusion process, ensuring that the upscaled images retain the desired level of detail and aesthetic quality. This node is an essential tool for artists aiming to push the boundaries of their creative projects by producing high-resolution outputs that are both visually appealing and technically sound.

DiffuseHighSampler Input Parameters:

model

The model parameter represents the AI model used for generating the image. It is crucial as it defines the base capabilities and style of the output. This parameter does not have specific minimum or maximum values, as it depends on the model being used.

x

The x parameter is a torch.Tensor that serves as the initial input image or data. It is the starting point for the diffusion process, and its quality and resolution can significantly impact the final output. There are no specific value constraints, but it should be compatible with the model's input requirements.

sigmas

The sigmas parameter is a torch.Tensor that defines the noise levels used during the diffusion process. It plays a critical role in controlling the denoising steps, with typical values ranging from 0.3 to 0.5 for effective upscaling. Using a sigma value of 1.0 is not recommended as it may lead to undesirable results.

diffusehigh_options

The diffusehigh_options parameter is a dictionary containing various configuration settings for the diffusion process. These options allow for customization of the sampling behavior, enabling users to tailor the process to their specific needs. The exact options available depend on the implementation details.

disable

The disable parameter is a boolean that, when set to True, disables the progress bar during the sampling process. This can be useful for reducing visual clutter in the user interface. The default value is None, which means the progress bar is enabled by default.

extra_args

The extra_args parameter is an optional dictionary that allows users to pass additional arguments to the sampler. This flexibility can be used to fine-tune the sampling process or integrate with other components. The default value is None, indicating no extra arguments are provided.

callback

The callback parameter is an optional callable function that can be executed at specific points during the sampling process. It provides a mechanism for users to implement custom behavior or logging. The default value is None, meaning no callback function is used.

DiffuseHighSampler Output Parameters:

SAMPLER

The SAMPLER output is the primary result of the DiffuseHighSampler node. It represents the enhanced sampling process that can be connected to other nodes supporting a SAMPLER input. This output is crucial for integrating the high-resolution sampling capabilities into larger workflows, allowing for the generation of detailed and high-quality images.

DiffuseHighSampler Usage Tips:

• Ensure that the sigmas parameter is set to a value between 0.3 and 0.5 to achieve optimal denoising and upscaling results.
• Utilize the diffusehigh_options to customize the sampling process according to your specific artistic needs, allowing for greater control over the final output.

DiffuseHighSampler Common Errors and Solutions:

"All iterations skipped, cannot return a result from sampler!"

• Explanation: This error occurs when the sampling process is unable to perform any iterations, possibly due to incorrect configuration or input parameters.
• Solution: Verify that all input parameters are correctly set and that the iterations parameter is greater than zero to ensure the sampling process can proceed.

"Initial reference sigmas must end at 0 (full denoise)"

• Explanation: This error indicates that the sigmas parameter does not end with a value of 0, which is required for the initial reference image generation.
• Solution: Adjust the sigmas tensor to ensure that the last value is 0, allowing for a complete denoising process during the initial reference image generation.