ComfyUI Node: Tonemap (simple)

Tonemap (simple):

The CV2Tonemap node is designed to apply tone mapping to high dynamic range (HDR) images, converting them into a format suitable for display on standard monitors. Tone mapping is a crucial process in image processing that helps in compressing the range of luminance values in an HDR image to a more manageable range, preserving details in both the shadows and highlights. This node leverages OpenCV's tone mapping algorithms to achieve this, making it easier for you to work with HDR images and produce visually appealing results. By adjusting parameters such as gamma and multiplier, you can fine-tune the tone mapping process to suit your artistic needs, ensuring that your images retain their intended look and feel.

Tonemap (simple) Input Parameters:

image

This parameter expects an image input in the form of a tensor. The image should be in a high dynamic range format, which means it contains a wide range of luminance values. The tone mapping process will be applied to this image to compress its dynamic range.

gamma

The gamma parameter controls the gamma correction applied during the tone mapping process. Gamma correction adjusts the brightness of the image, with higher values making the image brighter and lower values making it darker. The default value is 1.0, with a minimum of 0.0 and a maximum of 8.0, adjustable in steps of 0.01.

mult

The mult parameter is a multiplier that scales the final output image after tone mapping. This allows you to adjust the overall intensity of the image. The default value is 1.0, with a minimum of 0.0 and a maximum of 8.0, adjustable in steps of 0.01.

Tonemap (simple) Output Parameters:

IMAGE

The output is an image tensor that has undergone tone mapping. This image will have a compressed dynamic range, making it suitable for display on standard monitors while preserving details in both the shadows and highlights. The output image is ready for further processing or direct use in your projects.

Tonemap (simple) Usage Tips:

• Experiment with the gamma parameter to find the right balance of brightness and contrast for your image. A higher gamma value can help bring out details in darker areas, while a lower value can enhance highlights.
• Use the mult parameter to fine-tune the overall intensity of the image after tone mapping. This can help in achieving the desired visual effect without losing important details.
• Combine the CV2Tonemap node with other color correction nodes to further enhance the visual quality of your images.

Tonemap (simple) Common Errors and Solutions:

Color conversion failed! Missing cv2 op 'COLOR_<src>2<dst>'

• Explanation: This error occurs when the specified color conversion operation is not available in the installed version of OpenCV.
• Solution: Ensure that you have the correct version of OpenCV installed that supports the required color conversion operations. You may need to update or reinstall OpenCV.

AssertionError: Color conversion failed! Missing cv2 op 'COLOR_<src>2<dst>'

• Explanation: This error indicates that the specified source and destination color spaces for conversion are not supported.
• Solution: Verify that the source and destination color spaces are correctly specified and supported by OpenCV. Refer to the OpenCV documentation for a list of supported color spaces.

TypeError: 'NoneType' object is not callable

• Explanation: This error occurs when the tone mapping operation is not available in the installed version of OpenCV.
• Solution: Ensure that you have the correct version of OpenCV installed that includes the tone mapping functions. You may need to update or reinstall OpenCV.