spidrweb by Dewey Odhner with 5 x 5 anti-aliasing

I saw a thumbnail of this image on the FractInt Deep Zoom webpage. The image looked interesting but at the time there was no parameter file. What was there was a short description of the history behind this image by Dewey Odhner. Quoting the FractInt Deep Zoom webpage:

"This is a deepzoom image into the Mandelbrot using 63 decimal digits of precision. Dewey started this fractal and posted the partial image on the net when it was 2/3 completed after expending approximately 2343 hours of calculation time on a 486/33 computer."

Wow, 2343 hours and still only a partial image. How did he ever find it and zoom in on a fractal that draws that slow. When asked, Dewey revealed his technique:

"I found the spidrweb minibrot by looking at areas around larger minibrots and learning to recognize where they occur, what the areas tend to look like as you look on smaller buds and closer to the tip of the bud. I tried to find the largest minibrot within that distance of the bud tip."

A little searching on the web turned up the parameter file but without the color palette. Paul Lee came to the rescue with the original gif image that contained the parameters and the color palette. Paul also updated the FractInt Deep Zoom webpage to include the parameter file and the original gif image. Here is the original parameter file with colormap:

spidrweb   { ; (c) by Dewey Odhner.  Public domain.  26 Jun 1995
 ; time=2413:22:56.14 on a 486/33 at 1024x768x256
 ; Video=SF7 using FractInt 19.20
 reset=1920 type=mandel passes=1 float=y inside=0 maxiter=65535
 144784316302197739437/4.4e+058 params=0/0 logmap=yes
 CIscU<2>mbU  }

It draws a lot faster on todays hardware of course. It still took 38 minutes and 45 seconds for Fracton to draw the 1024 x 768 image with no anti-aliasing on my fastest computer (Mac Pro 2 x 2.8 GHz Quad-Core Xeon). The 5 x 5 anti-aliased image would take 25 times longer to draw. That was way too long to tie up my main computer so I moved it to an older and much slower Dual 2 GHz PowerPC G5 Mac. There it took 116 hours to draw the top image at 5 x 5 anti-aliasing. This is still one slow fractal.

While I was looking for the original color palette, I found one I liked and made the image below:


spidrweb by Dewey Odhner with the Chakotay color map and linear color mapping

Change the parameter file to use linear color mapping instead of the original log. The Chakotay color map is:

Chakotay_Map { ; From Paul Lee's map collection
 NpVOsXQuYRxZSy_Tz`Tz`Uz`T }


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