# Questions tagged [gaussian-blur]

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### How is Gaussian Blur Implemented?

I've read that blur is done in real time graphics by doing it on one axis and then the other. I've done a bit of convolution in 1D in the past but I am not super comfortable with it, nor know what to ...
1k views

### How does directional Gaussian blurring work?

In image editing software, you often have the ability to do a directional blur where you can choose and angle and a magnitude of a blur. How does this actually work in practice with Gaussian blurring? ...
440 views

### Texture prefiltering for Linearly Transformed Cosines

I'm implementing Real-Time Polygonal-Light Shading with Linearly Transformed Cosines from Siggraph 2016. I'm stuck on the texture prefiltering (section 5.3). As I understand they use ...
67 views

### Plotting pbrt-v3 Gaussian filter

I want to plot the Gaussian filter of pbrt-v4 with a radius $(100,100)$ and a standard deviation ($\sigma$) of $0.5$. I would expect something like this: When I plot the pbrt-v4 Gaussian filter with ...
1 vote
64 views

### What denoising filter gives highest quality for indirect light image?

Some background of my scenario: I have two images of indirect radiance, both are from an animation. I will reproject an pixel from the previous frame to current frame, and I want to do comparisons ...
144 views

### How is the multiplication in Gaussian Blur implemented

I have a question regarding how the Gaussian blur works. A pixel consists on the combination of 3 colors: R,G and B. I have read that the Gaussian kernel is multiplied by the input image by placing ...
5k views

### Is doing multiple Gaussian blurs the same as doing one larger blur?

To make Gaussian blurring a 2d image faster, I know that you can do one axis and then the other. I'm wondering though, if I did two Gaussian blurs of size $N$, would that be the same mathematically ...
1 vote
1k views

### Blurring image with RGB values without convolving it with a kernel

I'm using an app for face redaction that doesn't allow access to the source code but only allows me to pass pixel values for red, green and blue channel upon which it creates a matrix with the same ...
3k views

### Bokeh from depth map

How do I generate bokeh that simulates shallow depth of field given a perfect depth map? Here's what I tried: Generated a sample scene using blender and corresponding depth map Using Python, ...
2k views

### Why do multiple Gaussian Blurs?

Applying multiple Gaussian blurs can result in an effect that is equivalent to a stronger Gaussian blur. For instance this question says that: Is doing multiple Gaussian blurs the same as doing one ...
143 views

### gaussFactorForOffset cannot call a non-function how to fixed this code?

Crossposted here http://forum.lwjgl.org/index.php?topic=6724 Hello guys I am trying to blur image using fragment shader but it is not smooth.. I search the internet and I found similar problem... ...
1k views

### Does a gaussian blur based bloom/glow shader require gamma correction? Any other tips?

Hello I have a simple application with some bright 2d mono-color shapes I am hoping to make appear emissive with a nice glow around them. To do that I am producing multiple gaussian blurs of varying ...
216 views

I am working on a specific blur effect that implies several behaviours. But before I would like to know what you think about those blurring algorithms according to performances and quality : Kawase ...
102 views

### Replace a chain of image blurs with one blur

In this question I asked how to implement a chain of blurs in one single step. Then I found out from the gaussian blur page of Wikipedia that: Applying multiple, successive gaussian blurs to an ...
245 views

### How does this app pull off fast, high radius HDR

I am in awe at this app I just found. It was actually one of the first things I installed when I first bought my iPad 2 but now they have updated it to add an HDR effect. I have never seen a real-...
138 views

### How can I implement a complex sinusoidal function?

The following is the 2d complex sinusoidal function, $u_0$ and $v_0$ represent Fundamental Frequencies in $X$ and $Y$ directions respectively. How can I represent $j$ (imaginary number)? Edit: ...
117 views

### Where are the highlight definitions inside of my shader?

I have a pretty good glow shader going now thanks to some tips from people here. However there are a few things that bother me that could maybe be better. #1 Definition of the particles A lot of ...
146 views

### Will the gaussian kernels in this fragment shader be computed for every fragment?

I am running this fragment shader on every pixel on screen. I am trying to make it as efficient as possible. BTW I am running open gl es 2.0. The code segment below is only a sample from the code, ...