UM:Dvo Effects Dvo Grain GT

From DigitalVision
Jump to: navigation, search

Darrow-up.png     Previous Next

DVO Grain GT
From Release : 2017.1

DVO Grain GT is a fast grain management tool based on DVO Grain that makes full use of modern advanced CPU instruction sets.

The Digital Vision DVO Grain algorithm is specifically designed to manage the look of film grain and to reduce unwanted electronic noise in film or video originated material. Uses include :

  • Restoration
  • Compression pre-processing
  • Image processing of new feature film, television and commercial material.

The DVO Grain GT algorithm incorporates the Digital Vision Emmy award-winning PHAME advanced motion estimation technology along with edge-preserving 3-D spatio-temporal filters and temporal (recursive) filters to allow artists to produce clean, sharp pictures and to match the look of film grain from shot-to-shot (including grain matching for underexposed film). The process of adaptively selecting the best mix of spatial and recursive filtering for each pixel is unique to the DVO Grain algorithm.

DVO Grain GT Effects Settings

This toggle button will enable or disable the entire DVO Grain GT tool :

Dvo grain gt enable.png

Data Format

The Data button selects the input image data format.

Values Linear, Log
Default Linear

It is important to set the data format correctly as it has a fundamental and important affect on the processing.

Basic Mode

Dvo grain gt basic.png

The DVO Grain GT Basic Mode provides simple control of the grain/noise reduction without sacrificing performance. This is a good starting point and may be all that is required.

Basic Mode will use only the settings in the first column shown above (except Data which is independent) :

  • Mode - a preset
  • Amount - mix with input
  • Strength - how much effect

Note :

  • Adjusting any of the other DVO Grain GT parameters (e.g. Temporal or Spatial Strength, Spike Filter, Motion Estimation etc.) will automatically disable Basic Mode.
  • Selecting a particular Mode (e.g. Film Coarse) will automatically enable Basic Mode.
Mode (Presets)

The Mode sets the basic preset used for the grain reduction. Each selected mode will setup the more advanced parameters automatically.

Values Film Fine, Film Medium, Film Coarse, Video (Interlaced), Video (Progressive)
Default Film Medium

The amount of grain/noise reduction is set automatically in Basic Mode. This control lets you tune this, and increase or decrease the amount of grain reduction done.

Values -2 - +2
Default 0

Amount controls the mix between the processed image (with grain removed) and the input image to give the final output image.

This makes it possible to mix in some of the original grain into the processed picture for a better film look.

Values 0 - 100%
Default 100%
Advanced Methods

Leaving Basic Mode, we have an array of advanced modes and settings available to tune all aspects of the effect.

The best course of action is often to choose a Basic Mode preset that most closely matches your desired result and then adjust one or more advanced settings.

Temporal Strength

Dvo grain gt temporal strength.png

The temporal or recursive filtering is the most effective filter in terms of reducing grain/noise.

Range 0 - 15
Default 7

Use the numeric sliders to set the amount/level of temporal recursive filtering in each channel.

Global / Global Balance

Dvo grain gt global.png

As an adaptive grain and noise reducer, we disable the temporal/recursive processing of all moving edges within the image to assist in the reduction of motion artifacts.

Turning on Global enables filtering of the whole picture regardless of motion for maximum temporal filtering.

Global should normally be left Off and only used in extreme situations, or to create a motion smearing effect.

Global Balance

Global Balance allows a combination of the basic level of spatial filtering and motion adaptive spatial filtering.

Maximum filtering according to spatial strength is achieved in areas with motion.

The Global Balance slider allows you to to set a minimum level of spatial filtering, rather than having the level set entirely based on motion detection.

  • Set to 0 (zero) - parts of the image with no motion will receive no spatial filtering
  • Increasing the slider - increases the spatial filtering of areas with little or no motion

Global spatial filtering can be achieved by setting Global Balance to 100.

Note :

  • Temporal filtering works in areas with no or little motion.
  • Spatial filtering works in areas of motion.
  • Global enable the filters to work on the entire picture.
Spatial Filtering

Edge-preserving spatial filtering complements the adaptive temporal filters by processing grain and noise in portions of the image that are detected as being in motion, while leaving non-moving areas unaffected.

The spatial filtering is done before application of the temporal filters and works in unison with the motion processing.

Spatial Strength

Dvo grain gt spatial strength.png

Spatial Strength is the overall level of spatial filtering applied in each channel. The values here should normally match the temporal strength.

Range 0 - 15
Default 7
Spatial Size

Dvo grain gt spatial size.png

The Spatial Size drop-down list adjusts the spatial size of the grain/noise in pixels for each channel.

Values 1, 3, 5, 7, 9
Default 7

Setting R, G and B equally will give best performance.

Spatial Threshold

Dvo grain gt spatial threshold.png

The spatial threshold determines when to filter, depending on the intensity of the surrounding pixels.

Range 0 - 100
Default 16

If there is a high enough intensity/contrast (e.g. an edge) between the grain/noise and surrounding pixels, filtering will not occur.

A low setting will only affect low intensity pixels (flat areas). A high setting will start to affect high intensity pixels (edges).

Spatial Filter

Dvo grain gt spatial filter.png


If this is enabled, the filter becomes a 3D Spatio-Temporal Filter (adding the use of temporal taps). This can enhance the noise reduction achieved.

Default On
Temporal Mix

The temporal mix controls the balance between the spatial and temporal taps of the spatio-temporal filter.

Values Low, Medium, High, Full
Default High

This setting affects the noise reduction achieved by the spatio-temporal filter, with more noise reduction for the higher settings.

For fast motion material and a higher than default spatial filter threshold setting, a high temporal mix setting may increase artifacts. In such cases, this setting may be lowered. For a lower than default spatial filter threshold setting, the Full setting may be used.

The default setting High should be safe in most circumstances.

Spike Filter

This setting enhances the spatial filter performance by incorporating a spike adaptation.

Values Disable, Narrow, Medium, Wide
Default Medium

The Spike Filter setting relates to the grain/noise characteristics :

  • A low setting (e.g. Narrow) is suitable for smaller grain and noise sizes and/or less pronounced variations in amplitudes.
  • A high setting (e.g. Wide) is suitable for larger grain/noise and/or more pronounced variations in amplitudes.

Setting this to Narrow in conjunction with setting Motion Sensitivity to High and Motion Estimation to Best can help avoid motion estimation errors caused by noisy/grainy material.


Dvo grain gt motion.png

DVO Grain GT is a fully motion compensated noise/grain reducer. This means that much more aggressive settings can be used without introducing smearing.

Motion Estimation
Values Disable, Normal, Best
Default Normal

The Best setting is good for fast motion but is slower than Normal.
In almost all cases, Normal or Best should be used.

Motion Sensitivity

Motion Sensitivity adapts the temporal filtering with respect to grain size and intensity.

Values Low, Medium, High
Default Medium

Motion Sensitivity has great impact on processing and the type of filter (spatial/temporal) being used.

It may be better to set Motion Sensitivity to Low rather than just increasing filter strengths.


Dvo grain gt video.png

For video source material.

Process YUV

Enable to process in YUV colourspace (not RGB).


Enable to process fields (not frames).

Darrow-up.png     Previous Next