Author Archives: Peter Stampfli
Anti-aliasing for improving image quality
About a year ago I have briefly shown in my post “smoothing images” that averaging can be important to get good images without pixel noise. For my kaleidoscope app, see http://geometricolor.ch/sphericalKaleidoscopeApp.html, I have improved on these ideas and that’s what … Continue reading
Bridges 2018 Stockholm
I have been at the Bridges 2018 conference in Stockholm to present my work on kaleidoscopes. My paper “Kaleidoscopes for Non-Euclidean Space” has more details than this blog and is more coherent. The Bridges Organization, which promotes connections between mathematics … Continue reading
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
Decorations of semi-regular tessellations
In the last posts I have shown kaleidoscopes that make repeating images in Euclidean, spherical and hyperbolic spaces. They are decorations of regular tilings. But what about semi-regular tilings? Could we decorate them too using mirrors? This would give us … Continue reading
further wallpapers for hyperbolic space
An equilateral triangle gives us a kaleidoscope of three-fold rotational symmetry. With a square we get two-fold rotational symmetry. Would reflection at the sides of other regular polygons too give periodic images with rotational symmetry ? To get an h-fold … Continue reading
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
Elliptic kaleidoscopes
In “further hyperbolic kaleidoscopes” I used two straight lines and a circle to make a triangle that defines a kaleidoscope. For k,n and m-fold rotational symmetries at its corners, the sum of its three angles is π(1/k+1/n+1/m). If this sum is … Continue reading
