Logo by Transdimensional - Contribute your own Logo!

END OF AN ERA, FRACTALFORUMS.COM IS CONTINUED ON FRACTALFORUMS.ORG

it was a great time but no longer maintainable by c.Kleinhuis contact him for any data retrieval,
thanks and see you perhaps in 10 years again

this forum will stay online for reference
News: Visit us on facebook
 
*
Welcome, Guest. Please login or register. March 29, 2024, 12:40:31 AM


Login with username, password and session length


The All New FractalForums is now in Public Beta Testing! Visit FractalForums.org and check it out!


Pages: 1 [2]   Go Down
  Print  
Share this topic on DiggShare this topic on FacebookShare this topic on GoogleShare this topic on RedditShare this topic on StumbleUponShare this topic on Twitter
Author Topic: dense image  (Read 10719 times)
0 Members and 1 Guest are viewing this topic.
youhn
Fractal Molossus
**
Posts: 696


Shapes only exists in our heads.


« Reply #15 on: November 25, 2014, 03:42:46 PM »

Oh, and thanks for sharing the link to mathoverflow. The second answers is indeed very good. Did not know there was a name for it ... The hairiness theorem (source: http://mathoverflow.net/questions/187842/is-there-an-almost-dense-set-of-quadratic-polynomials-which-is-not-in-the-inte )
Logged
Adam Majewski
Fractal Lover
**
Posts: 221


WWW
« Reply #16 on: September 08, 2017, 07:53:35 PM »

https://www.math.univ-toulouse.fr/~cheritat/wiki-draw/index.php/Mandelbrot_set
see downsacling with gamma correction
Logged
claude
Fractal Bachius
*
Posts: 563



WWW
« Reply #17 on: September 12, 2017, 04:14:56 PM »

Nice link, some formulas there are new to me (Henriksen's boundary detection method, distance estimator normal map).

Typically images are in non-linear sRGB colour space.  To downscale correctly, you need to do that in linear colour space:

input sRGB image -> convert to linear RGB image -> downscale (= low pass filter -> decimate) -> convert back to sRGB image -> output sRGB image

the formulas for sRGB conversion are on wikipedia:  https://en.wikipedia.org/wiki/SRGB#Specification_of_the_transformation
Logged
Tglad
Fractal Molossus
**
Posts: 703


WWW
« Reply #18 on: September 13, 2017, 03:40:29 AM »

There was a discussion on this a few years back: http://www.fractalforums.com/sterlingware/to-anti-alias-or-not-to-anti-alias-hit-the-button-or-leave-it-alone/

A nice answer is to use the local fractal dimension of the set to control the antialiasing. The local fractal dimension doesn't mean 2 for the Mandelbrot set, it is what the set looks like at a particular point and zoom depth... so is local in position and scale.

In the pic below the left image shows how supersampling makes tendrils fade out, the right image shows that if you give every point in the set a half-pixel width, then the result is too thick. The middle image shows the new local-fractal-dimension based method.

I published a paper on this: http://ieeexplore.ieee.org/document/7138673/ (paywalled unfortunately), and a short blog post: http://tglad.blogspot.com.au/2012/12/dimension-aware-rasterising.html


* hires (1).png (50.3 KB, 793x289 - viewed 381 times.)
Logged
Pages: 1 [2]   Go Down
  Print  
 
Jump to:  

Related Topics
Subject Started by Replies Views Last post
3d printed dense Julia set Format, Printing & Post Production s31415 2 3334 Last post June 17, 2012, 04:05:33 PM
by s31415
Dense Rain Forest FractInt Gallery simon.snake 0 1306 Last post January 28, 2014, 01:43:30 AM
by simon.snake
Dense Jungle Images Showcase (Rate My Fractal) laser blaster 3 1748 Last post October 18, 2014, 10:10:53 PM
by laser blaster
Dense Tapestries Movies Showcase (Rate My Movie) stardust4ever 2 1021 Last post April 26, 2016, 10:43:47 AM
by stardust4ever
Dense deformed trees Images Showcase (Rate My Fractal) Dinkydau 2 932 Last post March 11, 2017, 02:55:14 AM
by Dinkydau

Powered by MySQL Powered by PHP Powered by SMF 1.1.21 | SMF © 2015, Simple Machines

Valid XHTML 1.0! Valid CSS! Dilber MC Theme by HarzeM
Page created in 0.338 seconds with 27 queries. (Pretty URLs adds 0.006s, 2q)