ComfyUI Node: Frequency Combine

Frequency Combine:

The FrequencyCombine node is designed to merge high-frequency and low-frequency components of images, allowing you to create unique visual effects by manipulating these frequency layers. This node is particularly useful for enhancing or altering specific details in an image, such as sharpening edges or blending textures. By combining the high-frequency and low-frequency images using either subtraction or division methods, you can achieve a variety of artistic effects that can enhance the overall aesthetic of your work. The node provides flexibility in how the frequencies are combined, making it a powerful tool for image processing and creative experimentation.

Frequency Combine Input Parameters:

high_frequency

This parameter accepts an image that represents the high-frequency components, which typically include fine details and edges. The high-frequency image is crucial for adding or enhancing details in the final output.

low_frequency

This parameter accepts an image that represents the low-frequency components, which generally include the broader, smoother areas of the image. The low-frequency image helps to maintain the overall structure and color gradients in the final output.

mode

This parameter determines the method used to combine the high-frequency and low-frequency images. It can be set to either "subtract" or "divide". The "subtract" mode will subtract the low-frequency image from the high-frequency image, while the "divide" mode will divide the high-frequency image by the low-frequency image, adjusted by a small epsilon value to prevent division by zero. This choice significantly impacts the resulting image's appearance.

eps

This parameter is a small floating-point value used in the "divide" mode to prevent division by zero. It has a default value of 0.1, with a minimum of 0.01 and a maximum of 0.99, adjustable in steps of 0.01. The epsilon value ensures numerical stability during the division process and can subtly influence the final image.

Frequency Combine Output Parameters:

IMAGE

The output is a single image that results from the combination of the high-frequency and low-frequency input images. This image will reflect the chosen combination method and the specific details and structures from both input images, providing a unique visual effect.

Frequency Combine Usage Tips:

• Experiment with both "subtract" and "divide" modes to see which method best suits your artistic vision for the image.
• Adjust the eps parameter in small increments to fine-tune the results when using the "divide" mode, ensuring that the image does not suffer from artifacts due to division by zero.
• Use high-quality high-frequency and low-frequency images to achieve the best results, as the quality of the input images directly affects the output.

Frequency Combine Common Errors and Solutions:

Image size mismatch

• Explanation: The high-frequency and low-frequency images must be of the same dimensions.
• Solution: Ensure that both input images are resized to the same dimensions before using the FrequencyCombine node.

Invalid mode selection

• Explanation: The mode parameter must be set to either "subtract" or "divide".
• Solution: Double-check the mode parameter to ensure it is correctly set to one of the allowed values.

Division by zero artifacts

• Explanation: When using the "divide" mode, very small values in the low-frequency image can cause artifacts.
• Solution: Increase the eps parameter slightly to prevent division by zero and reduce artifacts in the output image.