ComfyUI Node: ProPostApplyLUT

ProPostApplyLUT:

The ProPostApplyLUT node is designed to apply a Look-Up Table (LUT) to an image, allowing you to achieve sophisticated color grading effects. This node is particularly useful for enhancing the visual aesthetics of your images by adjusting their color tones and contrasts based on predefined LUTs. By blending the original image with the LUT-applied image, you can control the intensity of the effect, making it a versatile tool for both subtle and dramatic color transformations. The node also supports logarithmic adjustments, which can be beneficial for working with images in different color spaces or dynamic ranges.

ProPostApplyLUT Input Parameters:

image

This parameter represents the input image to which the LUT will be applied. The image should be in a tensor format, typically with dimensions corresponding to batch size, height, width, and color channels.

lut_name

This parameter specifies the name of the LUT file to be applied to the image. The LUT file should be located in the directory specified by folder_paths.get_filename_list("luts"). The LUT file contains the color transformation data that will be used to adjust the image's colors.

strength

This parameter controls the intensity of the LUT effect on the image. It is a floating-point value ranging from 0.0 to 1.0, where 0.0 means no effect (original image) and 1.0 means full effect (completely LUT-applied image). The default value is 1.0, allowing for maximum color transformation.

log

This boolean parameter determines whether logarithmic adjustments should be applied to the image before and after the LUT application. When set to True, the image undergoes a gamma correction process, which can be useful for images in different color spaces. The default value is False.

ProPostApplyLUT Output Parameters:

IMAGE

The output is the image with the LUT applied, returned in the same tensor format as the input image. This output image reflects the color transformations specified by the LUT and the blending strength, providing a visually enhanced version of the original image.

ProPostApplyLUT Usage Tips:

• To achieve subtle color adjustments, set the strength parameter to a lower value, such as 0.2 or 0.3.
• Use the log parameter for images that require gamma correction, especially if you are working with high dynamic range (HDR) images.
• Experiment with different LUT files to find the one that best suits the mood and tone you want to convey in your image.

ProPostApplyLUT Common Errors and Solutions:

"LUT file not found"

• Explanation: The specified LUT file could not be located in the directory.
• Solution: Ensure that the LUT file name is correct and that it is located in the directory specified by folder_paths.get_filename_list("luts").

"Invalid LUT format"

• Explanation: The LUT file is not in a supported format or is corrupted.
• Solution: Verify that the LUT file is in a compatible format (e.g., .cube) and is not corrupted. Try using a different LUT file.

"Image tensor shape mismatch"

• Explanation: The input image tensor does not have the expected dimensions.
• Solution: Ensure that the input image tensor has the correct dimensions, typically in the format (batch_size, height, width, color_channels).

"Strength value out of range"

• Explanation: The strength parameter is set to a value outside the allowed range of 0.0 to 1.0.
• Solution: Adjust the strength parameter to a value within the range of 0.0 to 1.0.