ComfyUI Node: 🖼️ Fallback Image Previewer

🖼️ Fallback Image Previewer:

The FallbackImagePreviewer node is designed to handle scenarios where image previews are required but the primary image data is unavailable or invalid. This node ensures that a fallback mechanism is in place to generate a placeholder image, maintaining the workflow's continuity and preventing interruptions. It is particularly useful in AI art generation pipelines where image previews are essential for iterative design processes. By providing a fallback image, it helps you visualize the output even when the primary image data is missing, thus enhancing the robustness and reliability of your image processing tasks.

🖼️ Fallback Image Previewer Input Parameters:

images

This parameter accepts the primary image data that you want to preview. If valid images are provided, they will be used for generating the preview. If this parameter is None, the node will proceed to generate a fallback image. This parameter is crucial as it determines whether the node will use the actual image data or create a placeholder.

fallback_width

This parameter specifies the width of the fallback image to be generated if the primary image data is unavailable. It ensures that the generated placeholder image has the correct dimensions. The width should be a positive integer, and a value of 0 indicates that no valid fallback image will be generated.

fallback_height

This parameter specifies the height of the fallback image to be generated if the primary image data is unavailable. Similar to fallback_width, it ensures that the generated placeholder image has the correct dimensions. The height should be a positive integer, and a value of 0 indicates that no valid fallback image will be generated.

save_image

This boolean parameter determines whether the generated image (either primary or fallback) should be saved to disk. If set to True, the image will be saved, and additional parameters like filename_prefix will be used to determine the file name and location.

filename_prefix

This parameter is used to specify the prefix for the filename when saving the image. It helps in organizing and identifying the saved images, especially when multiple images are generated in a batch process. This parameter is only relevant if save_image is set to True.

prompt

This parameter is used to provide additional context or metadata for the image being generated. It can be useful for documentation or for embedding extra information within the image file. This parameter is optional and is primarily used for informational purposes.

extra_pnginfo

This parameter allows you to embed additional PNG metadata into the generated image. It is useful for storing extra information that can be retrieved later, enhancing the image's utility in various applications. This parameter is optional and is only relevant if save_image is set to True.

🖼️ Fallback Image Previewer Output Parameters:

ui

This output parameter contains a dictionary with the key images, which holds the generated image(s). The images can be either the primary images provided as input or the fallback images generated by the node. This output is essential for further processing or visualization in the workflow.

result

This output parameter returns a tuple containing the original images provided as input. If no valid images were provided, it returns None. This output is useful for debugging and for ensuring that the original input data is preserved and can be accessed later in the workflow.

🖼️ Fallback Image Previewer Usage Tips:

• Ensure that the fallback_width and fallback_height parameters are set to appropriate values to generate a meaningful fallback image when the primary image data is unavailable.
• Use the save_image parameter wisely to save only the necessary images, as saving every generated image can consume significant disk space.
• Utilize the filename_prefix parameter to organize your saved images effectively, especially when working with batch processes.

🖼️ Fallback Image Previewer Common Errors and Solutions:

"NO VALID IMAGES RECEIVED! IGNORING..."

• Explanation: This error occurs when no valid images are provided as input, and both fallback_width and fallback_height are set to 0.
• Solution: Ensure that either valid images are provided as input or set appropriate values for fallback_width and fallback_height to generate a fallback image.

"NO VALID IMAGES RECEIVED! GENERATING EMPTY IMAGE."

• Explanation: This message indicates that no valid images were provided, but the node is generating a fallback image based on the specified fallback_width and fallback_height.
• Solution: Verify that the dimensions for the fallback image are correctly set to generate a meaningful placeholder image.