Blur Filters

Simple blur

Simple blur applies a simple blur convolution to the buffer, known as a box filter. Every pixel is averaged equally with each of its neighbors. The result is a slightly blurry image.  The effect can then be faded to meet your needs.

 If you plan on performing further convolution such as edge detect, then consider using the Gaussian blur filter instead, as it produces a more natural blur effect.


 

Box filter

The box filter blurs an image in a very simple, but fast way. Each pixel is averaged with a number of ifs horizontal and vertical neighboring pixels with equal weighting.

Gaussian blur



Gaussian blur performs a blur where each pixel is averaged with pixels in a radial pattern, with the center pixel receiving the greatest weight. The effect is very similar to a real-world blur from a camera lens with a blur filter.

There are 3 modes, including approximate, hybrid and precise. The approximate mode is more triangular than curved in nature, but can be calculated much faster than a true Gaussian blur. The results are visually very similar. The hybrid modes uses an approximation for a preview, then performs a precise calculation for a final result.

Bokeh blur

The Bokeh blur filter can useful for creating 'circle of confusion' effects like those that are produce inside a real camera lens system.


In the CPU version, the dynamic range is limited to that of the image, so you don't get the same 'blowout' that you would get from intense values.

The GPU version will also allow you to select an upper range of your images intensity values to blow out to simulate camera “Bloom,” in which case you can specify a shutter shape for the bloom effect to adhere to. This can produce very realistic camera blur like effects, using only a 24 bit image.

The GPU version will run automatically if supported by your system and if GPU support is enabled in settings.




Here, a simulated depth-of-field effect was created from a deep focus image taken with a cheep digital camera. An alpha channel was created with the linear alpha fader tool, and Bokeh blur was applied to the selected part of the image. The blur of the effect was controlled by the value in the alpha channel (selection,) so that higher values in the alpha channel caused that part of the image to have more blur.

A bloom effect (the hexagonal glowing parts of the image) was created using a combination of Bloom and Threshold settings.


 

Motion blur

The motion blur filter creates the effect of motion blur by blurring the image by a vector in a single direction. There are two settings, Faster and Better, which should be self-explanatory. To be specific, the faster setting only calculates every other pixel.



 

Zoom blur

The zoom filter creates the effect of motion blur while zooming toward or into an image.  You can center the effect and change the intensity (factor) and quality of the blur.  Lower quality settings render faster, but may look 'stair stepped'.

The GPU version will run automatically if supported by your system and if GPU support is enabled in settings.


 

Mystic vision

The Mystic vision filter is directly related to the zoom filter, however the results have different uses.  The mystic vision filter is used to create glow effects, such as those  shining through a forest on a misty afternoon, or like the beams of light you see in a sunset.

Mystic vision can also be used to make glowing logos, or special effects, such as “Mystic Knights” transformations.

The Scary setting combines the effect with a Less Than (<) blend mode instead of Greater than (>) so the beams appear darker than the rest of the image instead of lighter.

The GPU version will run automatically if supported by your system and if GPU support is enabled in settings.

Chroma blur



The Chroma blur filter blurs the chrominance channel (the color component) of an image, leaving the details intact.

This is useful for reducing noise that is restrained mainly to the color component of the image. It can also be useful for various special effects.




Radial blur

Radial blur creates an effect similar to rotating your camera very quickly. The Factor setting controls how intense the motion blur effect is, and Quality helps to eliminate the stepping errors than might be visible, at the expense of taking longer to calculate.



Alpha aware blur unselected.

Sometimes you need to blur just part of an image. You might select part of your image to blur, or you may blur the unselected part, but the problem is with traditional blurring techniques, is that undesirable parts of your image will be factored into the blur.

For example, you have selected part of your image you want to protect from being blurred, say the foreground, and you blur the rest. The edges around the foreground look “glowey” because those edges are spilling into the blurred part of the image.


Alpha aware blur unselected works by factoring out the parts of the image that are selected, so that they are never considered as part of the image that is being blurred. It can produce very usable effects, but it is a very intensive calculation, and may occasionally produce false results.