Neat Image user guide / Filtration process details / Stage III. Adjust filter settings

Adjust filter settings (Advanced mode)

As compared with the Standard mode (see the Adjust filter settings (Standard mode) subsection), the Advanced mode offers a more sophisticated sets of filter controls. There are also two main filters - noise reduction filter and sharpening filter - but these have more adjustable settings now. Please follow the guidelines below to enable / disable and adjust both filters.

Adjusting noise filter settings in Advanced mode

In the Advanced mode, the noise filter has separate settings for all frequency and channel components of the input image. There are pairs of noise level - noise reduction amount controls for each of these image components. The meaning of each noise level - noise reduction amount pair is the same as explained in the Adjusting noise filter settings in Standard mode: a noise level control determines which image elements are considered noise in corresponding image component; a noise reduction amount control determines how much reduction is applied to the image elements identified as noise.

Because the noise level controls are relative to the device noise profile, their defaults usually produce good results. The noise level defaults are 0% (some of the noise level defaults may be different from 0%), which means the noise levels are completely determined by the noise profile. When the level controls are set differently, the noise level estimations are raised or lowered accordingly. A noise level can be in the range from -100%, which means no image elements are considered noise, and therefore, no noise reduction is applied in the corresponding image component; to +150%, which means noise reduction is applied to the image elements that are weaker than 250% of the noise profile's noise level.

Noise reduction amounts can be in the range from 0% (none of the detected noise is removed) to 100% (all the detected noise is removed). By default, the noise filter removes 100% of detected noise (some of the noise reduction amount defaults may be different from 100%).

Decreasing the noise reduction amounts can have a positive effect if the input image contains some natural noise. For example, when you filter images of asphalt, sand, or anything else that contains fine natural noise-like features, it may be helpful to reduce amounts down to 40-50% (see Partial filtration for additional tips). Our experience shows that these values generally provide a good balance between preserving image details and noise removal.

 

It is recommended to disable the sharpening filter when adjusting the noise filter. To disable the sharpening filter, uncheck all channels in the Sharpening Settings box.

Adjust noise reduction amounts (optional)

 

Adjust additional filter settings (optional)

 

Use preview

Adjust noise levels (optional)

 

Use Component Viewer (optional)

The Component Viewer is intended for detailed examination of both frequency and channel components of the image. Find more details about using this tool in the Component Viewer subsection.

 

Use Variant Selector (optional)

The Variant Selector is designed to compare several variants of filtration side-by-side to find the optimum filter settings easier and faster. More information about this tool is available in the Variant Selector subsection.

 

Adjusting sharpening settings in Advanced mode (optional)

Note: You can skip this subsection when reading for the first time.

The sharpening filter is designed to increase image sharpness without increasing the noise strength.

The default values of the sharpening settings should produce satisfactory results (when sharpening is enabled for any of the channel components) but you are encouraged to vary the settings to find values that produce the desired level of sharpness. Zero sharpening amounts will not sharpen the image at all. The non-zero sharpening amounts will apply sharpening of the specified strength. Use sharpening controls for different frequency components to sharpen fine, medium or large image details. As with any other sharpening method, you have to balance the amounts to avoid over-sharpening.

Use the preview when adjusting the sharpening settings.

 

Select color channels where sharpening should be applied

Select sharpening mode

Adjust sharpening amounts

Use preview

 

As soon as you are happy with the preview results regarding both noise reduction and sharpening, proceed to the subsection about saving the filter settings into a preset or to the Stage IV. Apply filter to the input image.