Tag Archives: python

Gradient-descent optimized recursive filters for deconvolution / deblurring

Posted on September 5, 2022 by bartwronski

This post is a follow-up to my post on deconvolution/deblurring of the images. In my previous blog post, I discussed the process of “deconvolution” – undoing a known convolution operation. I have focused on traditional convolution filters – “linear phase, … Continue reading →

Posted in Code / Graphics | Tagged algorithms, digital signal processing, graphics, graphics programming, image processing, jax, maths, numpy, python, signal processing | Leave a comment

Progressive image stippling and greedy blue noise importance sampling

Posted on August 31, 2022 by bartwronski

Introduction I recently read the “Gaussian Blue Noise” paper by Ahmed et al. and was very impressed by the quality of their results and the rigor of their method. They provide a theoretical framework to analyze the quality of blue … Continue reading →

Posted in Code / Graphics | Tagged algorithms, blue noise, dithering, graphics, graphics programming, image processing, jax, programming, python, sampling | 3 Comments

Transforming “noise” and random variables through non-linearities

Posted on March 16, 2022 by bartwronski

This post covers a topic slightly different from my usual ones and something I haven’t written much about before – applied elements of probability theory. We will discuss what happens with “noise” – a random variable – when we apply … Continue reading →

Posted in Code / Graphics | Tagged blue noise, graphics, graphics programming, image processing, jax, mathematics, maths, noise, programming, python | Leave a comment

Study of smoothing filters – Savitzky-Golay filters

Posted on November 3, 2021 by bartwronski

Last week I saw Daniel Holden tweeting about Savitzky-Golay filters and their properties (less smoothing than a Gaussian filter) and I got excited… because I have never heard of them before and it’s an opportunity to learn something. When I … Continue reading →

Posted in Code / Graphics | Tagged algorithms, digital signal processing, image processing, maths, python, signal processing | Leave a comment

Superfast void-and-cluster Blue Noise in Python (Numpy/Jax)

Posted on April 21, 2021 by bartwronski

This is a super short blog post to accompany this Colab notebook. It’s not an official part of my dithering / Blue Noise post series, but thematically fits it well and be sure to check it out for some motivation … Continue reading →

Posted in Code / Graphics | Tagged blue noise, dithering, graphics programming, jax, numpy, python | 3 Comments

Converting wavetables to Ableton Operator AMS waves

Posted on January 5, 2021 by bartwronski

This blog post comes with Ableton Operator AMS “wavetables” here. In Ableton’s FM synth you can use different types of oscillator waves as your operators (both carriers as well as modulators), as well as draw custom ones: What is not … Continue reading →

Posted in Audio / Music / DSP | Tagged ableton, digital signal processing, dsp, fourier, frequency domain, numpy, python, synthesis | 3 Comments

“Optimizing” blue noise dithering – backpropagation through Fourier transform and sorting

Posted on April 26, 2020 by bartwronski

Introduction This will be a blog post that is second in an (unanticipated) series on interesting uses of the JAX numpy autodifferentiation library, as well as an extra post in my very old post series on dithering in games and … Continue reading →

Posted in Code / Graphics | Tagged blue noise, dithering, frequency domain, image processing, jax, machine learning, noise, numpy, python | 8 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 | 11 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 | 16 Comments

Analyze your own activity data using Google Takeout – music listening stats example

Posted on January 6, 2020 by bartwronski

The goal of this post is to show how to download our own data stored and used by internet services to generate personalized stats / charts like below and will show step-by-step how to do it using colab, Python, pandas, … Continue reading →

Posted in Code / Graphics | Tagged colab, data, numpy, programming, python, statistics, visualization | Leave a comment

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 | 7 Comments

Python as scientific toolbox – 8 months later

Posted on September 16, 2014 by bartwronski

I started this blog with a simple post about my attempts to find free Mathematica replacement tool for general scientific computing with focus on graphics. At that time I recommended scientific Python and WinPython environment. Many months have passed, I … Continue reading →

Posted in Code / Graphics | Tagged algorithms, Anaconda, mathematica, python, sublime text, tools, winpython | 1 Comment

Updated Poisson-like generator with GUI and more

Posted on September 5, 2014 by bartwronski

Just a super short note: I updated my simple rendering-oriented Poisson-like pattern generator with: Very simple GUI made in PyQt to make experimenting easier. Option to do rotating disk (with minimizing rotated point distance) for things like Poisson bokeh / … Continue reading →

Posted in Code / Graphics | Tagged algorithms, Anaconda, antialiasing, graphics programming, mathematica, poisson, programming, pyqt, python, stochastic | Leave a comment

Poisson disk/square sampling generator for rendering

Posted on August 8, 2014 by bartwronski

I have just submitted onto GitHub small new script – Poisson-like distribution sampling generator suited for various typical rendering scenarios. Unlike other small generators available it supports many sampling patterns – disk, disk with a central tap, square, repeating grid. It … Continue reading →

Posted in Code / Graphics | Tagged algorithms, Anaconda, programming, python, stochastic, supersampling, temporal, tools, winpython | Leave a comment

On pursuit of (good) free mathematics toolbox

Posted on January 19, 2014 by bartwronski

Introduction Mathematics are essential part of (almost?) any game programmers work. It was always especially important in work of graphics programmers – all this lovely linear algebra and analytic geometry! – but with more powerful hardware and more advanced GPU … Continue reading →

Posted in Code / Graphics | Tagged graphics programming, mathematica, mathematics, python, sublime text, winpython | 1 Comment