Tag Archives: postprocessing

Processing aware image filtering: compensating for the upsampling

Posted on July 20, 2021 by bartwronski

This post summarizes some thoughts and experiments on “filtering aware image filtering” I’ve been doing for a while. The core idea is simple – if you have some “fixed” step at the end of the pipeline that you cannot control … Continue reading →

Posted in Code / Graphics | Tagged algorithms, digital signal processing, filtering, graphics, image processing, jax, postprocessing, signal processing | 5 Comments

Bilinear texture filtering – artifacts, alternatives, and frequency domain analysis

Posted on April 14, 2020 by bartwronski

In this post we will look at one of the staples of real-time computer graphics – bilinear texture filtering. To catch your interest, I will start with focusing on something that is often referred to as “bilinear artifacts”, trapezoid/star-shaped artifact … Continue reading →

Posted in Code / Graphics | Tagged blur, filtering, image processing, postprocessing, temporal, temporal supersampling | 11 Comments

Using JAX, numpy, and optimization techniques to improve separable image filters

Posted on March 15, 2020 by bartwronski

In today’s blog post I will look at two topics: how to use JAX (“hyped” new Python ML / autodifferentiation library), and a basic application that is follow-up to my previous blog post on using SVD for low-rank approximations and … Continue reading →

Posted in Code / Graphics | Tagged bokeh, colab, github, graphics programming, image processing, jax, machine learning, maths, numpy, postprocessing, programming, python | 9 Comments

Separate your filters! Separability, SVD and low-rank approximation of 2D image processing filters

Posted on February 3, 2020 by bartwronski

In this blog post, I explore separable convolutional image filters: how can we check if a 2D filter is separable, and how to compute separable approximations to any arbitrary 2D filter represented in a numerical / matrix form using SVD. Continue reading →

Posted in Code / Graphics | Tagged algorithms, approximation, blur, bokeh, depth of field, graphics, image processing, linear algebra, numpy, optimizations, postprocessing, python | 9 Comments

Local linear models and guided filtering – an alternative to bilateral filter

Posted on September 22, 2019 by bartwronski

Intro In this blog post I am going to describe an alternative tool for the graphics and image processing programmers’ toolbox – guided filtering. Guided filtering is a really handy tool that I learned about from my coworkers, and I … Continue reading →

Posted in Code / Graphics | Tagged bilateral, graphics, image processing, machine learning, postprocessing, python, signal processing, ssao, upsampling | 4 Comments

Separable disk-like depth of field

Posted on August 6, 2017 by bartwronski

This is a short note accompanying shadertoy: https://www.shadertoy.com/view/lsBBWy . It is direct implementation of “Circularly symmetric convolution and lens blur” by Olli Niemitalo (no innovation on my side, just a toy implementation) and got inspired by Kleber Garcia’s Siggraph 2017 presentation “Circular … Continue reading →

Posted in Code / Graphics | Tagged bokeh, depth of field, dof, far cry 4, Gaussian, maths, photography, poisson, postprocessing, separable, witcher 2 | 2 Comments

Image dynamic range

Posted on September 1, 2016 by bartwronski

Intro This post is a second part of my mini-series about dynamic range in games. In this part I would like to talk a bit about dynamic range, contrast/gamma and viewing conditions. You can find the other post in the series here and … Continue reading →

Posted in Code / Graphics | Tagged dynamic range, graphics, graphics programming, HDR, mathematica, mathematics, postprocessing, tonemapping, visuals | 13 Comments

Localized tonemapping – is global exposure and global tonemapping operator enough for video games?

Posted on August 29, 2016 by bartwronski

In this blog post, I wanted to address something that I was thinking about for many years – since starting working on rendering in video games and with HDR workflows and having experience with various photographic techniques. For the title … Continue reading →

Posted in Code / Graphics, Travel / Photography | Tagged exposure, film, God of War, graphics, graphics programming, photography, photos, postprocessing, tonemapping | 17 Comments

Anamorphic lens flares and visual effects

Posted on March 9, 2015 by bartwronski

Introduction There are no visual effects that are more controversial than various lens and sensor effects. Lens flares, bloom, dirty lens, chromatic aberrations… All of those have their lovers and haters. Couple years ago many games used cheap pseudo HDR effect … Continue reading →

Posted in Code / Graphics | Tagged algorithms, anamorphic, bokeh, C#, cinematography, depth of field, film, flares, graphics, graphics programming, history, lens, movies, photography, postprocessing, programming | 16 Comments

Designing a next-generation post-effects pipeline

Posted on December 9, 2014 by bartwronski

Hey, it’s been a while since my last post. Today I will focus on topic of post-effects. Specifically, I wanted to talk about next-gen post process pipeline and redesign I worked on while being a part of Far Cry 4 rendering team. … Continue reading →

Posted in Code / Graphics | Tagged 1080p, algorithms, bokeh, depth of field, far cry 4, graphics, graphics programming, photography, PlayStation 4, postprocessing, programming, tonemapping, Xbox One | 6 Comments

CSharpRenderer Framework update

Posted on October 18, 2014 by bartwronski

In couple days I’m saying goodbye to my big desktop PC for several next weeks (relocation), so time to commit some stuff to my CSharpRenderer GitHub repository that was waiting for it for way too long. 🙂 Startup time optimizations … Continue reading →

Posted in Code / Graphics | Tagged .NET, C#, framework, graphics, graphics programming, postprocessing, programming, tools | 15 Comments

Major C#/.NET graphics framework update + volumetric fog code!

Posted on August 20, 2014 by bartwronski

As I already promised too many times, here comes major CSharpRenderer framework update! As always, all code available on GitHub. Note that the goal is still the same – not to write most beautiful or fast code, but to provide a … Continue reading →

Posted in Code / Graphics | Tagged .NET, algorithms, C#, graphics, graphics programming, postprocessing, supersampling, temporal, temporal supersampling | 18 Comments

Digital Dragons 2014 slides

Posted on May 9, 2014 by bartwronski

This Friday I gave a talk on Digital Dragons 2014. It was a presentation with tons of new, unpublished content and details about our: Global Illumination solution – full description of baking process, storing data in 2D textures and runtime application Temporal … Continue reading →

Posted in Code / Graphics | Tagged assassin's creed, graphics, graphics programming, PlayStation 4, postprocessing, programming, Xbox One | 2 Comments

Temporal supersampling pt. 2 – SSAO demonstration

Posted on April 27, 2014 by bartwronski

This weekend I’ve been working on my Digital Dragons 2014 presentation (a great Polish game developers conference I was invited to – if you will be somewhere around central Europe early May be sure to check it out) and finally got … Continue reading →

Posted in Code / Graphics | Tagged algorithms, antialiasing, assassin's creed, graphics, graphics programming, next-gen, PlayStation 4, postprocessing, stochastic, supersampling, temporal, temporal supersampling, Xbox One | 7 Comments

Bokeh depth of field – going insane! part 1

Posted on April 7, 2014 by bartwronski

Recently I was working on console version depth of field suitable for gameplay – so simple, high quality effect, running with a decent performance on all target platforms and not eating big percent of budget. There are tons of publications about … Continue reading →

Posted in Code / Graphics | Tagged bokeh, depth of field, dof, graphics, graphics programming, postprocessing, programming, the witcher 2: assassins of kings, witcher 2 | 25 Comments

Temporal supersampling and antialiasing

Posted on March 15, 2014 by bartwronski

Aliasing problem Before I address temporal supersampling, just a quick reminder on what aliasing is. Aliasing is a problem that is very well defined in signal theory. According to the general sampling theorem we need to have our signal spectrum … Continue reading →

Posted in Code / Graphics | Tagged algorithms, antialiasing, assassin's creed, graphics, graphics programming, PlayStation 4, postprocessing, programming, stochastic, supersampling, temporal, temporal supersampling, Xbox One | 16 Comments

The future of screenspace reflections

Posted on January 25, 2014 by bartwronski

Introduction The technique was first mentioned by Crytek among some of their improvements (like screenspace raytraced shadows) in their DirectX 11 game update for Crysis 2 [1] and then was mentioned in couple of their presentations, articles and talks. In … Continue reading →

Posted in Code / Graphics | Tagged algorithms, assassin's creed, graphics, postprocessing, programming, raymarching, raytracing | 5 Comments