An optional input for attaching pre-calculated motion vectors, such as those created by VectorGenerator.

Denoise can generate motion vectors internally, but connecting this input may produce significantly faster results.

An optional input for attaching a separate noise file. If you’re working with complex footage that doesn’t have a convenient area for analyzing noise, you can use the Noise input to analyze noise from another image and apply the results to your footage.

Displays the GPU used for rendering when Use GPU if available is enabled. Local GPU displays Not available when:

• Use CPU is selected as the default blink device in the Preferences.

• no suitable GPU was found on your system.

• it was not possible to create a context for processing on the selected GPU, such as when there is not enough free memory available on the GPU.

You can select a different GPU, if available, by navigating to the Preferences and selecting an alternative from the default blink device dropdown.

Note:   Selecting a different GPU requires you to restart Nuke before the change takes effect.

When enabled, rendering occurs on the Local GPU specified, if available, rather than the CPU.

Note:  Enabling this option with no local GPU allows the script to run on the GPU whenever the script is opened on a machine that does have a GPU available.
You should also select this if you wish to render from the command line with the --gpu option.

See Nuke 15 Release Notes for more information on the GPUs Nuke supports.

Choose Film or Digital according to what type of footage you’re working with.

Choose what type of noise you’re dealing with:

• Constant - try this if you’re working on film footage with lots of detail and not too much noise in dark regions, or digital footage with lots of detail and not too much noise in light regions.

• Modulated - for most cases, this is a good option.

When enabled, blacks in the image are lifted toward white. This can be particularly useful if your image contains a lot of sub-blacks, areas of black with a value less than 0.

Choose the denoise profile to use:

• Constant - let Denoise look at the analysis region and remove the same amount of noise across all intensities. Constant is nearly always a good choice, but if you find that your denoise results are too smooth and adjusting DenoiseAmount and RollOff doesn’t help, you should try setting this to Automatic.

• Automatic - let Denoise estimate a noise profile automatically based on the entire ProfileFrame. This way, Denoise removes different amounts of noise from the shadow, midtone, and highlight areas of the Source image. When you first switch to automatic profiling, Denoise uses the current frame to calculate the profile. If you’d like to use a different frame, you need to set Profile Frame on the Profile tab to that frame and click the Recalculate Profile button.

Denoise always bases the noise profile on your Source footage, even if you’ve attached another clip to the Noise input.

You can use the TuneProfile controls to tweak both Constant and Automatic profiles.

Whether to output the denoised image or the noise that was removed:

• Result - output the denoised Source image.

• Noise - output the noise that was removed from the Source image. Only noise should be visible in this image. If you can see a lot of picture detail, it means the current settings are making Denoise work too hard and remove too much of the image, which leads to a soft result.

Sets the overall amount of noise to remove. Increase this to remove more noise, or decrease to keep more detail. A value of 0 removes no noise.

Sets the smoothness of the denoise thresholding.

A value of 1 equals hard thresholding. Any other value produces soft thresholding between the Denoise Amount and the Roll Off multiplied by Denoise Amount.

Sets the smoothness of the denoised image. This affects the underlying image rather than the noise detected.

In most cases, the default value of 1 works fine. However, you can try using this control if you’re not getting the correct smoothness level by adjusting the Denoise Amount.

Blends the denoised luminance with the image’s original luminance, bringing back some of the image detail in the result.

You might want to have this set to 1 when you’re working on denoising the footage, but for the final result, you’ll want to decrease it.

When enabled, Denoise attempts to sharpen the image at edges to prevent over-smoothing, though this can emphasize noise in some cases.

Temporal Processing

When enabled, uses frames either side of the current frame to perform temporal frame blending, which may produce a better denoise result.

Note:  The Motion input must be connected to enable Temporal Processing.

The number of frames used either side of the current frame is determined by the Temporal Frame Offset control.

When disabled, uses only the current frame to produce the denoise result.

Sets the variance allowed between regions in blended frames. Higher values attempt to blend more regions, but can lose image detail.

Note:  This control is only available when Temporal Processing is enabled.

Sets the number of frames, on either side of the current frame, used to calculate the denoise effect.

Note:  This control is only available when Temporal Processing is enabled.

Noise Analysis

When enabled, no analysis is performed. This is activated by default if you use the Import button to read a noise profile from an external file.

Enter the coordinates for the region from which you want to analyze noise.

You can adjust the following:

• x - the distance (in pixels) between the left edge of the image and the left side of the analysis box.

• y - the distance (in pixels) between the bottom edge of the image and the bottom edge of the analysis box.

• r - the distance (in pixels) between the left edge of the image and the right side of the analysis box.

• t - the distance (in pixels) between the bottom edge of the image and the top edge of the analysis box.

• w - the width of the analysis box. This is only available if you click the wh button.

• h - the height of the analysis box. This is only available if you click the wh button.

You can also use the analysis box in the Viewer to position the analysis region. This should be a flat area free from image detail, so no textures, edges, or shadows. The minimum size for the analysis region is 80x80 pixels. If the analysis region is too small, Denoise doesn’t analyze the footage or remove any noise.

By default, whenever the analysis box is altered, the internal analysis of the noise in that region reoccurs.

The frame at which to analyze the noise in the analysis region.

This field is automatically updated if you scrub to a new frame in the Viewer and reposition the analysis box.

Click this button to analyze the noise in your footage. This can be useful if you scrub to a new frame, don't move the analysis box, and want to reanalyze the noise from the new frame.

The name and location of an external analysis file. Click the Export button to save the analysis profile in this file, or Import to read the analysis profile from this file.

The analysis file can be any binary file - for example a plain text file (.txt).

Reads an analysis profile from an external analysis file (specified in Analysis File). This disables any controls that are read from the analysis file. To re-enable them, you can uncheck Lock Noise Analysis.

Saves an analysis profile to an external analysis file (specified in Analysis File).

Note:  If you’ve set Profile to Constant, only the controls that affect the analysis are saved in this file. By contrast, if you’ve set Profile to Automatic, both the analysis profile and the automatically calculated noise profile are exported.

Tune Frequencies

Enable this if you want to remove noise from high frequencies (fine detail).

Scales the threshold for fine noise removal.

Increase this value to remove more fine noise, or decrease it to keep more detail and fine noise. A value of 0 means no fine noise is removed, whereas 1 is the estimated threshold.

Enable this if you want to remove noise from medium frequencies.

Scales the threshold for medium noise removal.

Increase this value to remove more medium noise, or decrease it to keep more detail and medium noise. A value of 0 means no medium noise is removed, whereas 1 is the estimated threshold.

Enable this if you want to remove noise from low frequencies (coarse detail).

Normally, most of the noise occurs in the high and medium frequencies, so often you can disable the low frequency altogether.

Scales the threshold for low noise removal.

Increase this value to remove more low noise, or decrease it to keep more detail and low noise. A value of 0 means no low noise is removed, whereas 1 is the estimated threshold.

Enable this if you want to remove noise from very low frequencies (very coarse detail).

Normally, most of the noise occurs in the high and medium frequencies, so often you can disable the very low frequency altogether.

Scales the threshold for very low noise removal.

Increase this value to remove more very low noise, or decrease it to keep more detail and very low noise. A value of 0 means no very low noise is removed, whereas 1 is the estimated threshold.

Tune Channels

Scales the denoising threshold for the luminance channel. Increase this value to remove more noise, or decrease it to keep more detail and noise.

Scales the denoising threshold for the chrominance channel. Increase this value to remove more noise, or decrease it to keep more detail and noise.

The noise profile curve. The x axis represents image intensity, from dark areas on the left to lighter areas on the right. The y axis represents the relative amount of noise removed.

You can adjust the curve manually by dragging the points on the curve to a new location. To add more points to the curve, Ctrl/Cmd+Alt+click on the curve.

If you are not happy with your changes, click Reset Profile to reset the curve to its original shape.

Resets any changes you’ve made to the noise curve. This does not affect changes made using the Low Gain, Mid Gain, and High Gain controls.

This button has the same functionality as the Reset Profile button below.

Enable this to tune the noise profile by adjusting Low Gain, Mid Gain, or High Gain. This works in both the Constant and Automatic profiling mode.

Scales the denoising threshold in the low light areas of the Source image. For example, a value of 2 multiplies the threshold by 2. Everything below the threshold is considered noise and removed, while everything above the threshold is kept.

This control is only available when Tune Profile is enabled.

Scales the denoising threshold in the midtone areas of the Source image. For example, a value of 2 multiplies the threshold by 2. Everything below the threshold is considered noise and removed, while everything above the threshold is kept.

This control is only available when Tune Profile is enabled.

Scales the denoising threshold in the highlight areas of the Source image. For example, a value of 2 multiplies the threshold by 2. Everything below the threshold is considered noise and removed, while everything above the threshold is kept.

This control is only available when Tune Profile is enabled.

The frame at which to estimate the noise profile when Profile is set to Automatic.

This control is read only. If you want to change the profile frame, you need to scrub to a new frame in the Viewer and click Recalculate Profile.