@gaeel great! not power 4, sorry for the red herring. this is also called Tricorn or Mandelbar

@emsenn I use lightdm display login manager on Debian instead of gdm. not familiar with guix though

the bot works by iteratively zooming in. given a view, it computes a bunch of randomly zoomed in pictures, and replaces the view by the zoom that had the best score.

currently it computes 16 zooms at each iteration, and does 10 iterations. ideally the score gradually increases, but that doesn't always happen.

the final iteration's hiscore is rendered bigger.

the motivation is to have images that have a wide variation of regions of differing local fractal dimension, which I hope would give interesting textures

unfortunately it tends to go dark and stretched quite often...

oops I used 10% and 90% not 25% and 75%, avoids getting 0 scores to often

working on a to automatically explore for

the main problem is devising a fitness function, I came up with this:

1. for each pixel in the fractal, compute the local box dimension of its neighbourhood. use the gray value of each pixel as its measure. use square neighbourhoods of radius 1,3,7,15,..., with simple linear regression to get the slope of the log(measure)/log(neighbourhoodsize) graph

2. compute a histogram of all these dimensions (I simply sorted the array). then take as fitness metric the difference between 25% and 75% through the array: this is typically the width of the central bulge in the histogram.

I came up with this after skimming "Multifractal-based Image Analysis with applications in Medical Imaging" master thesis by Ethel Nilsson www8.cs.umu.se/education/exami , viewing the dimension image in geeqie with histogram overlayed was interesting. also inspired by mrob.com/pub/muency/deltahausd

@gaeel a pity! from the symmetry I guess at power 4 stuff?

claude boosted

June 20th


> Algorave+friends return to Corsica Studios for a two room featuring: Lil Data (PC Music) // Heavy lifting (Pickled Discs) x Graham Dunning (Fractal Meat) // Miri Kat (Establishment) // Deerful // Hard On Yarn Sourdonk Communion (Hmurd x peb) // Class Compliant Audio Interfaces x Hellocatfood (Computer Club/Keysound) // Digital Selves // Mathr // xname // BITPRINT // Deep Vain // Hortense // Tsun Winston Yeung // +777000 // Coral Manton // Rumblesan + more TBA

Had some system freezes recently: when `et` switches from rendering on all cores to saving PNG on only one core, there's a chance of a lockup. No logs, even with a virtual terminal active no messages are printed. Initially I thought it was amdgpu related but it happened without X running in one test...

Trying to get more info by having terminals with system monitoring scripts running fails too - because the extra CPU load seems to prevent the freeze 😥

enjoying this recent release on Mahorka netlabel
Sai - Random Motion Of Particles [mhrk217]
math rock, trip rock, experimental rock, ambient, ambient rock, post rock, experimental

I had trouble with one PDF. It had double-page spreads as JPEG, but `pdfimages` extracted each twice which doubled the file size (I guess they were referenced with cropping or something in the PDF). Moreover they were rotated, and colour files despite the content being monochrome. These incantations solved it for me, albeit doing twice as much work as necessary:

pdfimages -all input.pdf tmp
exiftran -i -2 *.jpg
for i in tmp-???.jpg ; do jpegtran -grayscale -copy none -crop 877x1240+0+0 $i > $i-l.jpg ; done
for i in tmp-???.jpg ; do jpegtran -grayscale -copy none -crop 877x1240+876+0 $i > $i-r.jpg ; done
ls tmp-*[02468].jpg-?.jpg > tmp.list
tesseract tmp.list output pdf

`jpegtran` is from `libjpeg-progs` on Debian-based Linux distributions. Not sure where `exiftran` is from, I already had it installed. It's better to use `jpegtran` than ImageMagick `convert` or other tools because it doesn't recompress (which is a lossy operation).

/ / Mandelbrot

Parameter data for (usually this is stored in image metadata, but Mastodon strips that out...):

z := z^p + c
z := (|x| + i |y|)^p + c
z := z^p + c



claude boosted

🚨 ⚠️ ⚠️ ⚠️
Urgent Linux advisory
⚠️ ⚠️ ⚠️ 🚨


Urgently run the following:

echo 0 | sudo tee /proc/sys/net/ipv4/tcp_sack

On all Linux hosts to work around the issue and then start patching your kernels

I can't use my onboard as an access point using for after all:

iw list | grep "Supported interface modes" -A 8
does not list "AP" :(

Would have saved me literally hours if this had been the first line of the guides - "first check that it's possible".

The spare USB dongle I have is not supported by Linux, apparently the chipset is supported via but I'm not keen, just so much easier to use an old ADSL router to host the wifi...

server from almost a decade ago works with two small changes:

in `rdex.wsgi` replace
```import Image```
```from PIL import Image```

in `/etc/systemd/system/multi-user.target.wants/mysql.service` add `--thread_stack=1048576` to the `ExecStart` command (it is no longer supported as a configuration file option it seems...)

need to tweak the client at some point, it's saving a lot of uninteresting images, not sure why...

I resumed work recently on my reaction-diffusion explorer stuff (project started 2008 or so).

Minor improvements to the code, mainly using texture arrays instead of separate textures or atlases, which as a bonus allows mipmaps to be used too for much smoother appearance.

I also added an backend to the code, because really dislikes my laptop's onboard sound card, xruns all over. OSS works fine at similar latencies.

Next steps include getting the rdex-server side of things running again (probably need to port from 2 to Python 3, and has been replaced by in I think).

Followed by setting up a WIFI hotspot from the machine's card with captive portal to the rdex-server website, and an Android app to access it in fullscreen (because the browser UI adds unsightly scrollbars that aren't necessary if the address bar is hidden).


Using and commands to make a out of image thumbnails sorted by average level:

montage -tile ${COLUMNS}x${ROWS} -geometry ${TILEWIDTH}x${TILEHEIGHT}+0+0 $( identify -colorspace RGB -format "%[fx:mean] %[filename]\n" in-*.png | sort -nr | cut -d\ -f 2 ) out.png &&
convert tmp.png -colorspace RGB -geometry ${WIDTH}x${HEIGHT} -colorspace sRGB out.png

I didn't yet figure out how to get the -correct colour space conversion to happen inside the montage's own rescaling, so I render at natural size and with convert afterwards.

The last image is the good result, the other two are gamma-incorrect, thus they appear too dark on screen (and presumably print too).

@gaeel complex power to real number like your second example is problematic as it is multi-valued (not a function). Picking just one branch (eg the principal square root branch for power 3/2) can lead to visible discontinuities...

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