ComfyUI Node: HaldCLUT

HaldCLUT :

The HaldCLUT node is designed to apply a Color Look-Up Table (CLUT) to an image, transforming its colors based on a predefined mapping. This process is particularly useful for achieving specific visual styles or color grading effects, such as those seen in film and photography. By using a HaldCLUT, you can quickly and easily apply complex color transformations to your images, enhancing their aesthetic appeal or matching a particular visual theme. The node also offers an optional gamma correction feature, which can adjust the image's brightness and contrast to better suit the applied CLUT. This makes the HaldCLUT node a powerful tool for AI artists looking to fine-tune the color profiles of their generated images.

HaldCLUT Input Parameters:

image

This parameter accepts the input image that you want to transform using the HaldCLUT. The image should be in a compatible format, typically provided as a tensor. The input image serves as the base upon which the color transformations will be applied.

hald_clut

This parameter allows you to select the specific HaldCLUT file to be used for the color transformation. The available options are dynamically generated from the files present in the system, and you can choose from a list of predefined CLUTs. Each CLUT file represents a different color mapping, and selecting a different one will result in a different color transformation of the input image.

gamma_correction

This parameter determines whether gamma correction should be applied to the input image before the HaldCLUT is applied. It accepts two options: True or False. When set to True, the image will undergo gamma correction with a gamma value of 1.0/2.2, which can help in achieving more accurate color transformations. When set to False, no gamma correction will be applied.

HaldCLUT Output Parameters:

image

The output parameter is the transformed image, which has undergone the color mapping defined by the selected HaldCLUT. The resulting image will have its colors adjusted according to the CLUT, and if gamma correction was enabled, the brightness and contrast will also be modified. This output image is typically returned as a tensor, ready for further processing or display.

HaldCLUT Usage Tips:

• Experiment with different HaldCLUT files to find the color transformation that best suits your artistic vision. Each CLUT file offers a unique color mapping, so trying out various options can yield interesting results.
• Use the gamma correction feature to fine-tune the brightness and contrast of your image. Enabling gamma correction can help achieve more natural-looking transformations, especially when working with images that have a wide range of tones.
• Combine the HaldCLUT node with other image processing nodes to create complex visual effects. For example, you can apply a HaldCLUT transformation followed by additional adjustments like sharpening or blurring to enhance the final output.

HaldCLUT Common Errors and Solutions:

FileNotFoundError: [Errno 2] No such file or directory

• Explanation: This error occurs when the specified HaldCLUT file cannot be found in the system.
• Solution: Ensure that the HaldCLUT file you selected exists in the specified directory. Verify the file path and name to make sure they are correct.

ValueError: Invalid gamma value

• Explanation: This error occurs when an invalid gamma value is provided for gamma correction.
• Solution: Ensure that the gamma correction parameter is set to either True or False. If you need to apply a specific gamma value, modify the code to accept and validate custom gamma values.

IndexError: list index out of range

• Explanation: This error occurs when the selected HaldCLUT file index is out of the valid range.
• Solution: Verify that the selected HaldCLUT file is within the available options. Check the list of HaldCLUT files and ensure that the index corresponds to a valid file.

TypeError: Image data cannot be converted to float

• Explanation: This error occurs when the input image data is not in a compatible format for processing.
• Solution: Ensure that the input image is provided in the correct format, typically as a tensor. Convert the image to the required format before passing it to the HaldCLUT node.