ComfyUI Node: HDR Export to EXR

HDR Export to EXR:

The HDRExportNode is a specialized tool designed for exporting High Dynamic Range (HDR) images into the EXR format, which is widely used in professional visual effects and compositing pipelines. This node ensures that the full dynamic range of the image data is preserved without normalization, allowing for accurate representation of radiance values. The EXR format supports linear radiance values with 32-bit float precision per channel, which is essential for maintaining the integrity of HDR data. This node is particularly beneficial for artists and professionals who require precise control over image data for post-processing and compositing tasks, as it provides a clean and intuitive interface for specifying filenames and output paths, similar to standard ComfyUI save nodes.

HDR Export to EXR Input Parameters:

hdr_image

This parameter represents the HDR image tensor that you wish to export. The tensor can contain values that exceed 1.0, which is typical for HDR images as they capture a wider range of luminance levels than standard images. This parameter is crucial for ensuring that the exported file retains the full dynamic range of the original image.

filename_prefix

This string parameter allows you to specify the base filename for the exported image, excluding the file extension. By default, it is set to "ComfyUI". This prefix helps in organizing and identifying exported files, especially when dealing with multiple outputs.

output_path

An optional string parameter that defines the directory where the exported file will be saved. If left empty, the default path is ComfyUI/output. You can specify a subfolder by using a relative path (e.g., /subfolder) or provide a full custom path. This flexibility allows you to manage your file organization effectively.

counter

This integer parameter acts as a frame or sequence counter, starting from a default value of 1. It can range from 0 to 99999 and is incremented by 1. This is useful for exporting sequences of images, ensuring each file has a unique name.

format

This parameter lets you choose the file format for the export, with options being "exr" or "hdr". The default is "exr", which is preferred for its compatibility with professional compositing software. This choice affects how the image data is stored and accessed in post-production workflows.

bit_depth

This parameter determines the precision of the EXR file, with options for "16bit" or "32bit". The default is "32bit", which offers maximum quality by preserving the full range of HDR data. Choosing "16bit" can result in smaller file sizes but may compromise data precision.

compression

This parameter specifies the type of compression to apply to the EXR file, with options including "none", "rle", "zip", "piz", and "pxr24". The default is "zip", which provides a balance between file size and compression speed. The choice of compression can impact both the file size and the time it takes to save the file.

HDR Export to EXR Output Parameters:

filepath

The output parameter is the filepath of the exported HDR image. This string indicates where the file has been saved on your system, allowing you to easily locate and access the exported image for further use or processing. The filepath is crucial for verifying the success of the export operation and for subsequent file management tasks.

HDR Export to EXR Usage Tips:

• Ensure that the hdr_image tensor contains values above 1.0 to fully utilize the HDR capabilities of the node, as this will preserve the high dynamic range in the exported file.
• Use the filename_prefix and counter parameters effectively to organize and manage multiple exports, especially when working with sequences or batches of images.
• Choose the bit_depth and compression settings based on your quality and file size requirements. For maximum quality, opt for 32-bit depth and minimal compression.

HDR Export to EXR Common Errors and Solutions:

Latent stack processing failed

• Explanation: This error occurs when there is an issue processing the latent stack, possibly due to incorrect input data or a processing bug.
• Solution: Verify that the input hdr_image tensor is correctly formatted and contains valid HDR data. Check for any updates or patches to the node that might address known issues.

Could not verify saved HDR file

• Explanation: This warning indicates that the node was unable to confirm the integrity of the saved HDR file, possibly due to file corruption or incorrect save parameters.
• Solution: Ensure that the output path is correct and accessible. Double-check the format, bit_depth, and compression settings to ensure they are compatible with your system and software.