Bilateral Blur effect
The Bilateral Blur effect selectively blurs
an image so that edges and other details are preserved. Areas with
high contrast—where pixel values differ by a large amount—are blurred
less than areas of low contrast.
The primary
difference between the Bilateral Blur effect and the Smart Blur
effect is that edges and details are still blurred a small amount
by the Bilateral Blur effect. The result is a softer, dreamier look
than that achieved by the Smart Blur effect with equivalent settings.
The result of the Bilateral Blur effect is very similar to the
result of the Surface Blur filter in Adobe Photoshop.
Eran Stern provides a demonstration of the Bilateral Blur effect
on the Motionworks website.
This effect works with 8-bpc, 16-bpc, and 32-bpc color.
The Bilateral Blur effect preserves the details in the logo
and face.
- Threshold
- The radius of the blur is automatically decreased in areas
where an edge or other prominent detail feature exists. The Threshold
value determines how the Bilateral Blur effect decides what areas
contain features to be preserved and what areas should be blurred
by the full amount. A lower Threshold value causes more fine details
to be preserved. A higher Threshold value causes a more simplistic
result, with fewer details preserved.
- Radius
- A larger radius for a blur means that more pixels are averaged
together to determine each pixel value, so increasing the Radius
value increases the blurriness.
- Colorize
- When Colorize is not selected, the Bilateral Blur effect
operates on one value for each pixel: its luminance value, which
is a weighted average of its R, G, and B color channel values. The
result is a monochromatic image.
When Colorize is selected,
the Bilateral Blur effect operates on each color channel individually.
The result is a color image.
