UM:Dvo Effects 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 :
- 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.
This toggle button will enable or disable the entire DVO Grain GT tool :
The Data button selects the input image data format.
It is important to set the data format correctly as it has a fundamental and important affect on the processing.
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
- 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.
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)|
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|
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%|
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.
The temporal or recursive filtering is the most effective filter in terms of reducing grain/noise.
|Range||0 - 15|
Use the numeric sliders to set the amount/level of temporal recursive filtering in each channel.
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 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.
- 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.
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 is the overall level of spatial filtering applied in each channel. The values here should normally match the temporal strength.
|Range||0 - 15|
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|
Setting R, G and B equally will give best performance.
The spatial threshold determines when to filter, depending on the intensity of the surrounding pixels.
|Range||0 - 100|
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).
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.
The temporal mix controls the balance between the spatial and temporal taps of the spatio-temporal filter.
|Values||Low, Medium, High, Full|
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.
This setting enhances the spatial filter performance by incorporating a spike adaptation.
|Values||Disable, Narrow, Medium, Wide|
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 is a fully motion compensated noise/grain reducer. This means that much more aggressive settings can be used without introducing smearing.
|Values||Disable, Normal, Best|
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 adapts the temporal filtering with respect to grain size and intensity.
|Values||Low, Medium, High|
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.
For video source material.
Enable to process in YUV colourspace (not RGB).
Enable to process fields (not frames).