YABI – Yet Another Boids Implementation (simulation of flocking animals)

Just before I started my paternity leave I saw a documentary about flocking animals and how these can be modeled in computer simulation. I found it very exciting and eagerly thought I could implement a simulation in a days work. I, however, quite underestimated the free time available while on paternity leave and the project extended in to many pieces spread over a few weeks. First a little teaser from the animation I made using python and Matplotlib, where the Boids (birds, fish or flying sheep ..) are in blue and predators are in red:

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Photography: Channel mixer RGB values equivalent to traditional B&W film

I have a Nikon D90 DLSR and and from time to time I want to convert color photographs these into B&W photos. I use the open-source and completely free GIMP to edit the pictures and do B&W conversion.

Using the built-in grey scale conversion often doesn’t come out to nicely, so I was wondering how to emulated the classic B&W films using the channel mixer in GIMP. I turns out that Petteri Sulonen on his blog www.prime-junta.net had done just that. On the left I am showing the Channel Mixer window in Gimp to converting a color photography using the Ilford XP2 Super channel settings. Below is list of his findings (I have done this mainly to have a online copy in case his blog goes offline).

My only small contribution is a ZIP file with all the profiles saved as GIMP channel mixer settings files, so the profiles can easily be loadd: GIMP-BW-film-Channel-Mixer.zip 6KB.

Film Name Red Green Blue
Agfa 200x 18 41 41
Agfapan 25 25 39 36
Agfapan 100 21 40 39
Agfapan 400 20 41 39
Ilford Delta 100 21 42 39
Ilford Delta 400 22 42 37
Ilford Delta 400pro 31 36 33
Ilford FP4 28 41 31
Ilford HP5 23 37 40
Ilford SFX 33 36 31
Ilford XP2 Super 21 42 37
Kodak Tmax 100 24 37 39
Kodak Tmax 400 27 36 37
Kodak Tri-X 25 35 40