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Category Archives: programming
Straight lines in elliptic and hyperbolic space
A straight line is the shortest path between two points. Discussing curved space we would better call them geodesic lines to avoid confusion. I want to discuss these geodesic lines for surfaces of a sphere, elliptic space and hyperbolic space. … Continue reading
Posted in Kaleidoscopes, programming
Tagged elliptic geometry, geodesic line, hyperbolic geometry, Poincaré disc, straight line
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How to program fast kaleidoscopes
This post repeats parts of earlier posts but I am trying to expand the ideas and explain them better. First, I am showing you how to make rosettes with rotational symmetry and mirror symmetry. This is easier than making kaleidoscopic images, … Continue reading
Five fold rotational symmetry: Tuning the harmonics
In “better images from higher harmonics ?” I have replaced the basic sine and cosine functions by Fourier series approaching a symmetric triangular wave. This gave images with more details and somewhat smaller bullseyes. Here I want to show similar results … Continue reading
Smoothing images
The image quality suffers if the mapping functions X(x,y) and Y(x,y) of the position (x,y) of a pixel of the output image to the position (X,Y) of the sampled input image pixel are strongly contracting or expanding. For contracting mappings … Continue reading
Posted in Kaleidoscopes, programming
Tagged kaleidoscope, programming, smoothing images
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Better images from higher harmonics ?
Maybe you have noticed that a lot of round shapes without details in the recent images of this blog. They resemble bullseyes. Here is an example: It’s a periodic image with square symmetry and no mirror symmetry. Its big grey … Continue reading
Posted in Anamorphosis, Kaleidoscopes, programming
Tagged anamorphosis, kaleidoscope, programming
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Color symmetry upon rotation
Now I want to present color symmetry upon rotation for periodic and quasiperiodic kaleidoscopes. We have n different versions how to show the pixel colors of the input image in the new output image. For a color symmetry we have … Continue reading
Rotational symmetry from space with an odd number of dimensions
We now look at the easier case for the post “Quasiperiodic and periodic kaleidoscope from higher dimensional space“, where the embedding space has an odd number of dimensions, p=2q+1. The unit vectors lie at equal angles and form a star … Continue reading