Image Filters

Image Filters

Image Filters can be used to sharpen your rendered image or apply other standard filters.

Sharpen Filter

Image Filters are used to sharpen up your rendered image or apply other filters after rendering with IRender nXt .

Use the Tone Operator /Filters icon to launch the filters wizard after the rendering has started, (or is complete.)


  • See: Tone Operator for Tone Operation sliders.
  • Undo / Redo - remove or restore filters you have applied.
  • Remember Filters - if this is checked, then the filters will
    be remembered and reapplied the next time you render this model.
  • Reset - reset Tone Operator or Filters to the default values.
  • Reset All - reset both Tone Operator or Filter settings.


Original Image

Original Image

A Brick House downloaded from the 3D warehouse - with an IRender nXt tree and an HDRi background sky.

Original rendering - 32 passes.


Sharpen Filter

Software sharpening creates enhanced sharpness by making the edges more contrasty. The algorithm notices when colors or intensities change in the image and sharpens up the transitions.

Just a little sharpening can add detail to a rendering.


Soften Filter

Softening smooths out the transitions at "edges" - where the color or the intensity changes.


The Smooth Filter blends pixels together to create a smoother image.

One good application is when there are unresolved pixels from the Path Tracer. These will resolve better with more passes. However, sometime, the Smooth filter can help smooth out the image.
(This rendering has Volumetric Fog applied.)

Fog scene after 42 passes with Path Tracer - no Filters.
Same scene after applying Smooth Filter. Notice that many of the unresolved pixels are smoothed out.


Gamma Filter

Gamma filtering changes the intensities of colors to work better when displayed on a CRT screen.

In the early days of television it was discovered that CRT's do not produce a light intensity that is proportional to the input voltage. Instead, the intensity produced by a CRT is proportional to the input voltage raised to the power gamma. The value of gamma varies depending on the CRT, but is usually close to 2.5. In other words, the blue on one screen might well not be the same as the blue on another screen. A gamma filter attempts to correct for this.

For images which will be displayed on the web, you may want to add a gamma filter of about 2.5.


Gaussian 5x 5 Filter

A Gaussian Filter provides smoothing over a wider range (3 x 3 or 5 x 5) of pixels.


Emboss Filter

The Emboss filter creates the effect that an image is embossed into a thin metal plate


Edge Filter

The Edge Filter recognizes edge lines and displays only the edge lines.

See also