Logarithmic spiral, nautilus, and rainbow
The other day I stumbled into an interesting article on The Guardian online: The medieval bishop who helped to unweave the rainbow. In the article I learned for the first time of Robert […]
Monthly Archives: November 2014
Convert Matlab colormap to Surfer colormap
In the comment section of my last post, Steve asked if I had code to generate a Surfer.clr file from my Matlab colormaps. Some time ago I did write a […]
Spectral lightness rainbow colormap
Spectral lightness rainbow Quick post to share my replica of Ethan Montag ‘s Spectral lightness colormap from this paper. My version has a linear Lightness profile (Figure 1) that increases monotonically […]
New rainbow colormap: sawthoot-shaped lightness profile
Why another rainbow In the comment section of my last post Steve Eddins from Mathworks reported that some Matlab users prefer Jet to Parula, the new default perceptual colormap in Matlab, because within certain ranges […]
Visualizing colormap artifacts
In Evaluate and compare colormaps, I have shown how to extract and display the lightness profile of a colormap using Python. I do this routinely with colormaps, but I realize […]
Moiré Patterns
Moiré pattern Some time ago I reblogged a post from El Ojo Inoportuno showing Moiré pattern, which resulted from taking a photo of a circular pattern of (beautiful) tiles. This phenomenon is caused […]
What your brain does with colours when you are not “looking” – part 2
In What your brain does with colours when you are not “looking”, part 1, I displayed some audio spectrogram data (courtesy of Giuliano Bernardi at the University of Leuven) using 5 different colormaps to render the amplitude […]
Geophysical tutorial – How to evaluate and compare colormaps in Python
These below are two copies of a seismic horizon from the open source Penobscot 3D seismic survey coloured using two different colormaps (data from Hall, 2014). Do you think either of them is ‘better’? […]
