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Pekka Väänänen @pekkavaa.bsky.social · 1d

New article on my site: Better sRGB to greyscale conversion

The commonly used greyscale formula is slightly off when computed in gamma space but can it be fixed?

📜 30fps.net/pages/better...

A four-pane comparison of different formulas for greyscale conversion.
Top row: Linear sRGB (the correct way to do it), Gamma sRGB (the somewhat wrong "luma" formula).
Bottom row: CIELAB L* (a high quality option), and the new alternative gamma-space version.

Careful inspection shows the "Gamma sRGB" case is slightly dimmer at points than the others.

A quote from “Principles of Digital Image Processing” by Wilhelm Burger and Mark J. Burge. It shows weights that are a better fit for gamma-space greyscale conversion.

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Bart Wronski 🇺🇦🇵🇸 @bartwr.bsky.social · 4d

100% agree when it comes to the defaults, I thought it was extremely ugly, unreadable, and non-functional.
However, since I found this customization/setting, I started actually to enjoy it.

Reposted by Bart Wronski 🇺🇦🇵🇸

Bart Wronski 🇺🇦🇵🇸 @bartwr.bsky.social · 11d

A "healthy" alternative (though some would complain about cache ;] ): strided array views. Just return a strided view - no allocations needed. User can "compact" it if they want.
E.g. github.com/dsharlet/array a numpy-like multidimensional array powerhouse from my friend and a former coworker.

GitHub - dsharlet/array: C++ multidimensional arrays in the spirit of the STL

C++ multidimensional arrays in the spirit of the STL - dsharlet/array

github.com

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Bart Wronski 🇺🇦🇵🇸 @bartwr.bsky.social · 11d

A "healthy" alternative (though some would complain about cache ;] ): strided array views. Just return a strided view - no allocations needed. User can "compact" it if they want.
E.g. github.com/dsharlet/array a numpy-like multidimensional array powerhouse from my friend and a former coworker.

GitHub - dsharlet/array: C++ multidimensional arrays in the spirit of the STL

C++ multidimensional arrays in the spirit of the STL - dsharlet/array

github.com

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Reposted by Bart Wronski 🇺🇦🇵🇸

Mark Boss @markboss.bsky.social · 13d

Happy to announce: ReSWD. Sliced Wasserstein Distances are quite powerful, but they perform a Monte Carlo (MC) integration (over random directions). During an optimization this can lead to noisy gradients due to variance.

Project page: reservoirswd.github.io

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Reposted by Bart Wronski 🇺🇦🇵🇸

Baptiste GENEST @baptiste-genest.bsky.social · 14d

Computing the exact bijection of the optimal transport (OT) problem between very large point sets is completely untractable…

In our SIGGRAPH Asia 2025 paper: “BSP-OT: Sparse transport plans between discrete measures in log-linear time” we get one with typically 1% of error in a few seconds on CPU!

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Reposted by Bart Wronski 🇺🇦🇵🇸

Existential Comics @existentialcomics.com · 16d

The Three Wise Men -
existentialcomics.com/comic/622

The Three Wise Men

A philosophy webcomic about the inevitable anguish of living a brief life in an absurd world. Also Jokes

existentialcomics.com

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Jendrik Illner @jendrikillner.bsky.social · 16d

Graphics Programming weekly - Issue 410 - September 28th, 2025 www.jendrikillner.com/post/graphic...

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Reposted by Bart Wronski 🇺🇦🇵🇸

Aaron Hertzmann @aaronhertzmann.com · 15d

Here's a recording of my talk on how perspective works! If you're interested in learning about how picture perspective works in human vision, this is the video to watch. #visionscience
www.youtube.com/watch?v=eamc...

Picture Perspective and Our Eyes

YouTube video by Aaron Hertzmann

www.youtube.com

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Reposted by Bart Wronski 🇺🇦🇵🇸

ceruleite.bsky.social @ceruleite.bsky.social · 15d

#SIGGRAPH2025 Advances in Real-Time Rendering in Games course talks slides posted: "Adaptive Voxel-Based Order-Independent Transparency" shipping in the upcoming Call of Duty: Black Ops 7 by Michal Drobot from Activision Central Tech is now online: advances.realtimerendering.com/s2025/index....

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Bart Wronski 🇺🇦🇵🇸 @bartwr.bsky.social · 20d

Congratulations! :)

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Scott Anderson @impossible.bsky.social · 21d

There seems to be a phenomenon on Bluesky where if you talk about AI, even critically, in a way that isn't obviously disparaging, you're marked as an AI bro and blocked. The result is that leading AI ethicists are now "AI Bros" 🙄

Margaret Mitchell @mmitchell.bsky.social · 21d

I’m currently blocked by almost a quarter million users, mostly due to block lists asserting I’m a spammer (I am not), “AI bro” (I am not) or Generative AI user (I am not). There appears to be nothing I can realistically do if my time has value.

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Bart Wronski 🇺🇦🇵🇸 @bartwr.bsky.social · 21d

Reading this as I am rewriting a Python project to be 100% asyncio-based.😅
But I don't disagree! Harder to debug, harder to profile, there is overhead...
But also really nice to write - and read - for things that mix UI, disk operations, some slow background processing... 100x better than callbacks.

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Reposted by Bart Wronski 🇺🇦🇵🇸

Apoorva Joshi @apoorvaj.io · 22d

Insanely well-made video on EUV photolithography: www.youtube.com/watch?v=B248...

How are Billions of Nanoscopic Transistors Made into a Microchip? EUV Photolithography 🛠️⚙️🤯

YouTube video by Branch Education

www.youtube.com

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Bart Wronski 🇺🇦🇵🇸 @bartwr.bsky.social · 23d

NNs are ok and find some close-to-optimal local minima because of crazy overparametrized wastefulness leading to a super smooth loss landscape with infinite close-to-optima.

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Bart Wronski 🇺🇦🇵🇸 @bartwr.bsky.social · 23d

Everyone who tries differentiable programming encouraged by the success of NN training learns this lesson the hard way (so did I!). Most "functions" of a few+ variables, even when 100% differentiable, are so non-convex that getting optimal parameters is impossible from random start. :(

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Bart Wronski 🇺🇦🇵🇸 @bartwr.bsky.social · 23d

For optimizing a post filter, why do you need *all* rendering inputs being differentiable, do you need gradients of everything? Only things processing optimized variables need differentiability. (Maybe I misunderstood the application)
But as always - SGD might not be able to optimize them...

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Bart Wronski 🇺🇦🇵🇸 @bartwr.bsky.social · 23d

This looks absolutely fantastic! LLMs have great educational value and this is one of the best examples I have seen (as not replaceable by more "low tech" tools without existing total expertise)

Matt Godbolt @matt.godbolt.org · 23d

LLM-explanation is now live in @compiler-explorer.com - An example: compiler-explorer.com/z/rvvx7MxKq

* LLMs make mistakes and are overconfident
* We'll never force LLMs or AI on you, it's opt in (like clang-tidy, PVS Studio or other tools)
* It is *beta* quality

Initial results are promising(1/3)

Compiler Explorer - C++ (x86-64 clang 21.1.0)

// setup constexpr auto valid_chars = "0123456789abcdef"; bool is_valid_id(std::string_view maybe_id) { if (maybe_id.size() != 16) { return false; } if (maybe_id.find_first_not_of(valid_ch...

explain.compiler-explorer.com

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Bart Wronski 🇺🇦🇵🇸 @bartwr.bsky.social · 23d

The question is: what do you need it for. :) It generally works with some limitations, but for primary visibility or materials, you can assume it 100% solved. But its usefulness depends on application. Minor geometry tweaking? Great! Full scene reconstruction - forget - SGD itself is not enough.

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Bart Wronski 🇺🇦🇵🇸 @bartwr.bsky.social · 24d

Ok, kind of makes sense. I was replacing it myself and paying for it, but it was a while ago and I think the prices went up like crazy for that. On my previous phone I replaced it once after 1.5y, and now after 3y it was again getting unbearable (heavy use = 2x charges a day :( ).

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Bart Wronski 🇺🇦🇵🇸 @bartwr.bsky.social · 24d

That said, I absolutely cannot understand people who buy a new phone every year. Even ignoring the cost and the environmental impact, the hassle of setting it up (FU Microsoft Authenticator) is more than any truly perceivable benefit.

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Bart Wronski 🇺🇦🇵🇸 @bartwr.bsky.social · 24d

Got the new iPhone Pro - my usual 3 year phone cycle. After customizing the ugly and messy initial glass look (those home screen bubbles ugh), feels great! Not a groundbreaking update, but worth it. The screen, snappiness, new cameras and formats, styles, camera button (FINALLY!), USB-C. Good buy.

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Reposted by Bart Wronski 🇺🇦🇵🇸

Bart Wronski 🇺🇦🇵🇸 @bartwr.bsky.social · 24d

I think the H1Bs were broken, gaming the system, and the minimum required salary should be at least doubled.
(Based on personal experience: I didn’t win the literal H1B lottery)
But this is a) extortion, and b) destroying lives of existing H1B holders.
It will destroy any US skill-based industry.

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Bart Wronski 🇺🇦🇵🇸 @bartwr.bsky.social · 24d

Part that I missed yesterday: this is $100k extortion *per year*.
And for existing H1B holders as well! Basically making H1Bs useless for anyone but $1mm+ employees (that will likely use O1 anyway).
And it’s an application fee: so if they don’t approve it - *poof*. Money burned.

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Bart Wronski 🇺🇦🇵🇸 @bartwr.bsky.social · 24d

I think the H1Bs were broken, gaming the system, and the minimum required salary should be at least doubled.
(Based on personal experience: I didn’t win the literal H1B lottery)
But this is a) extortion, and b) destroying lives of existing H1B holders.
It will destroy any US skill-based industry.

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