This page provides information on the V-Ray denoising tool available on all platforms.
The V-Ray installation includes a standalone denoising tool called vdenoise that can be used to denoise still images or animations outside of Houdini. This is especially useful for animations because the standalone tool can look at multiple frames at once and produce a better denoising result. The vdenoise tool works with either .vrimg or multichannel OpenEXR files and writes out files with the same format.
The vdenoise tool is a part of the V-Ray for Houdini installation. You can quickly open a command prompt in the folder where the vdenoise tool is located, or run the executable to bring out vdenoise's GUI.
Currently, on all operational systems the vdenoise.exe is located in V-Ray's folder (where the V-Ray files are extracted) > appsdk > bin.
The denoiser needs several render elements in order to work optimally. The easiest way to generate these render elements is to add the Denoiser Render Channel to your Houdini scene.
To offset the frame number of the output file, use the the following flag:
-outputOffset=n
This takes an integer n to offset the output denoised frames of animation. The default value is 0, which does not offset the frame numbers.
For example, the following flags can be added to output frame numbers 0010, 0011, 0012, ..., 0030:
-frames=0-20 -outputOffset=10
Negative integers can be used as well. The following flags can be added to output frame numbers -004, -003, -002, ..., 0016:
-frames=0-20 -outputOffset=-4