ComfyUI Node: ◎ Radiance LUT Blend

◎ Radiance LUT Blend:

RadianceLUTBlend is a powerful node designed to blend two Look-Up Tables (LUTs) to achieve desired color grading effects in images. This node allows you to seamlessly combine the characteristics of two different LUTs, providing flexibility in color correction and creative color grading. By adjusting the blend factor and selecting the appropriate blend mode, you can control how the colors, saturation, and luminosity from each LUT are mixed. This capability is particularly beneficial for artists looking to fine-tune the visual aesthetics of their images, offering a range of blending modes such as Linear, Saturation, Luminosity, and Hue. The node ensures that the blending process is smooth and accurate, maintaining the integrity of the image while allowing for creative expression.

◎ Radiance LUT Blend Input Parameters:

image

The image parameter is the input image that you want to apply the LUT blending to. It serves as the base upon which the color grading effects will be applied. This parameter is crucial as it determines the starting point for the blending process.

lut_a

The lut_a parameter represents the first Look-Up Table (LUT) file. This LUT serves as one of the sources for the color grading effect. The characteristics of this LUT will be blended with those of lut_b based on the specified blend factor and mode.

lut_b

The lut_b parameter is the second Look-Up Table (LUT) file. Similar to lut_a, this LUT provides color grading characteristics that will be blended with lut_a. The combination of these two LUTs allows for a wide range of creative color grading possibilities.

blend_factor

The blend_factor parameter controls the degree to which each LUT influences the final output. It is a float value ranging from 0.0 to 1.0, where 0.0 means only lut_a is applied, and 1.0 means only lut_b is applied. The default value is 0.5, which results in an equal blend of both LUTs.

blend_mode

The blend_mode parameter determines the method used to blend the two LUTs. Options include "Linear," "Saturation," "Luminosity," and "Hue," each affecting the image differently. The default mode is "Linear," which blends the LUTs in a straightforward manner, while other modes offer more nuanced control over color and light blending.

strength

The strength parameter is a float value that adjusts the overall intensity of the blending effect. It ranges from 0.0 to 1.0, with a default of 1.0, allowing you to scale the effect from subtle to full strength.

clamp_output

The clamp_output parameter is a boolean that determines whether the output should be clamped to a 0-1 range. This is useful for ensuring that the output remains within standard displayable color ranges, especially when not working with HDR content.

log_space

The log_space parameter is a boolean that indicates whether the input image is log-encoded. When enabled, the node will decode the log-encoded input before applying the LUTs, ensuring accurate color grading.

log_encoding

The log_encoding parameter specifies the type of log encoding used if log_space is enabled. It allows you to choose from predefined log encodings, ensuring compatibility with various log-encoded inputs.

interpolation

The interpolation parameter determines the method used for interpolating between LUT values. Options include "Trilinear" and "Tetrahedral," with "Trilinear" as the default. This affects the smoothness and accuracy of the LUT application.

◎ Radiance LUT Blend Output Parameters:

blended

The blended parameter is the output image resulting from the LUT blending process. It reflects the combined effects of the two LUTs as specified by the blend factor and mode, providing a color-graded version of the input image.

◎ Radiance LUT Blend Usage Tips:

• Experiment with different blend modes to achieve unique color grading effects. Each mode offers a distinct way of combining the LUTs, which can dramatically alter the final image.
• Use the blend_factor to fine-tune the influence of each LUT. A value closer to 0.0 will favor lut_a, while a value closer to 1.0 will favor lut_b.

◎ Radiance LUT Blend Common Errors and Solutions:

"Invalid LUT file"

• Explanation: This error occurs when the provided LUT file is not in a recognized format or is corrupted.
• Solution: Ensure that the LUT files are correctly formatted and not corrupted. Try using a different LUT file to verify the issue.

"Blend factor out of range"

• Explanation: The blend factor must be between 0.0 and 1.0. Values outside this range are invalid.
• Solution: Adjust the blend factor to be within the valid range of 0.0 to 1.0.

"Interpolation method not supported"

• Explanation: The specified interpolation method is not recognized by the node.
• Solution: Choose a supported interpolation method, such as "Trilinear" or "Tetrahedral".