[Gimp-developer] ANNOUNCE: Mandelbrot Invert 1 and 2 plug-ins

2001-05-07 Thread Stan Schwartz

Hi,
My first plug-ins, but the writing seemed straight-forward enough. I
categorized them both as colormap (Image/Filters/Colors under GIMP v1.0).

Mandelbrot Invert 1 inverts image pixels to display a view of the
Mandelbrot set, generated within a user-selected rect of the complex plane.
If a sampled point within the rect is found to be a member of the M-set,
the color/value of the corresponding image pixel is inverted.

Mandelbrot Invert 2 inverts image pixels to display encirclement bands,
generated within a user-selected rect of the complex plane, that usually
appear adjacent the to Mandelbrot set.  The lower the number of iterations
required for the series sum calculated for a sampled point to diverge
beyond threshold, the more the color/value of the corresponding image
pixel is inverted.

Some samples of digital art I created using the algorithm for the first
plug-in (as a stand-alone program, before incorporation into the plug-in)
are viewable online in the Spotlight Corner of the Fractal Art Museum
http://www.crosswinds.net/~fractalis/spot/kodstans.html.  Thanks to
Joseph Trotsky for his generous comments.

A coherent and accessible write-up of the theory behind the Mandelbrot Set
is available in Gary William Flake's book, The Computational Beauty
of Nature.  This book was the starting point and inspiration for much of
this work.


Usage suggestions:
Both Mandelbrot Invert 1 and Mandelbrot Invert 2 start with a square
rect by default.  To get a more accurate depiction of the Mandelbrot set
(which may or may not be important to you), you should set the height/width
proportions of the complex plane rect to be the same as the height/width
proportions of your image or selection.  If it's not clear how to use
the first four parameters to resize/rescale/reposition the rect, try
doubling or cutting the default values in half to see the effect.  As
far as the other two parameters of Mandelbrot Invert 2, experiment.
If you go outside my suggested bounds, it shouldn't break anything (if it
does, let me know), but shouldn't output anything interesting either.
Note also that unlike most color filters, these also work on grayscale
images.  It's possible to get interesting abstract mist effects by
decomposing an image, applying one of the Mandelbrot Invert filters
to the saturation channel, and recomposing.


That's it.  Feedback, software development suggestions for
fixes/improvement, or interesting art use ideas/examples appreciated.

Later,
Stan Schwartz

 
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*  Stan Schwartz *
*  Post-Conceptual and Computational Art *
* [EMAIL PROTECTED] *
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Re: [Gimp-developer] ANNOUNCE: Mandelbrot Invert 1 and 2 plug-ins

2001-05-07 Thread Tom Rathborne

Stan;

You are into fractals, huh? 

I think you might enjoy these:
http://www.aceldama.com/~tomr/wx/xachtrans/

In particular, these are very pretty:
http://www.aceldama.com/~tomr/wx/xachtrans/ultraxach-still.png
http://www.aceldama.com/~tomr/wx/xachtrans/ultraxach-2.gif

Cheers,

Tom

-- 
Tom Rathborne [EMAIL PROTECTED] http://www.aceldama.com/~tomr/
Essentially this is what must be developed: the art of giving out in love and
intelligence what is taken in from vision and the experience of self-transcen-
dence and solidarity with the universe - A.Huxley to A.Hofmann, 1962-02-29
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[Gimp-developer] Comic strip artists use ...

2001-05-07 Thread Branko Collin


Just as an aside (see it as the Gimp developers appreciation day): I 
know this guy who is a professional comics artist. What does he use 
to draw his comics with? Photoshop? Picture Publisher? Illustrator? 
Deluxe Paint (ah, the memories...). The answer can be found here:

http://www.rocr.net/t4lb/t4lb-tedious.html


-- 
branko collin
[EMAIL PROTECTED]
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Re: [Gimp-developer] hi color pixel blending

2001-05-07 Thread Sven Neumann

Hi,

Deepak T [EMAIL PROTECTED] writes:

 I am writing a 2D 16 bit color arcade game.
 I have certain sprites (explosions, glows) which are drawn against a
 black background, when I draw these against a different background the
 sprite's edges do not blend with the background and the sprite
 looks bad, I am not talking about anti-aliasing here, I am talking
 about reading rgb of source pixel and combining it with rgb of destination
 pixel to make it look natural (the way it has been drawn against black
 background).

Either you have a real alpha channel or you should use a technique called 
color-keying, which means you draw only the parts of the sprites that are 
not a special color (black in your case). 

You can also try load the sprites into Gimp and use ColorToAlpha to convert 
black to an alpha channel. You might need to do some editing afterwards if 
your images contained black in the drawing itself. Then you'd have sprites
with real alpha channel and could do real alpha blending.

In any case, you want to use DirectFB (http://www.directfb.org/) for
your arcade game. Believe me...


Salut, Sven
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