Smoothing an image without losing all the edges, that’s what the Bilateral Filter is made for. It basically performs a Gaussian blur not only in the image dimensions, but also on the color intensities. Therefore it will smooth homogeneous areas while at the same time respecting the image’s edges. The following example shows the effect very well.

The current version is for Fusion 6.1 in 64 bit only. It provides the standard bilateral filter as well as the cross bilateral filter for grayscale and color images. DoD and RoI can be used to limit processing to a desired section of the image. Since the exact filter is very slow when applying large filter kernels, calculation in OpenCL with an optional approximation method is implemented as well. First tests on supported graphic cards show a speed up by a factor of 3-5 for OpenCL with default parameters. On gray scale images with large filter sizes, the approximation method can be more than a hundred times faster.

Download Bilateral Filter 1.2

We’re releasing a simple tool today to help you reduce noise in ’09. We develop many 3D filtering tools at AT, but this one is a good candidate for release because it’s useful for video compositing.

Download Median In Time 1.0

MedianInTime performs a median filter over time for each pixel. The median filter kernel can be selected from sizes 3,5,7 or 9 (indicating the total number of frames in the sort). The tool calculates the median based either on the luminance or the RGB channels separately. This operation will generally reduce noise, but is also great for removing things that appear for just one or two frames such as rain drops, film artifacts, and subliminal advertising.

I rendered two examples to demonstrate the technique. The first video shows how objects moving quickly in relation to other content can be removed with the median filter. In this example the stars moving in this time lapse footage are removed (as well as the odd shooting star).

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