Note: from 2024 January my webpages, previously hosted on https://www.mrao.cam.ac.uk/~dag/, are now being hosted on https://people.phy.cam.ac.uk/dag9/ instead. Please revise any bookmarks/links pointing to the old webpages.

Try ‘cubehelix’ colour scheme

This colour scheme is described in more detail in:

Green, D. A., 2011, ‘A colour scheme for the display of astronomical intensity images’, Bulletin of the Astronomical Society of India, 39, 289.

(2011BASI...39..289G at ADS.)

Please cite this paper if you use ‘cubehelix’ in any publications.

Using javascript, you can try out different ‘cubehelix’ colour schemes below, and optionally produce a ‘look-up-table’ file in several formats. Adjust the parameters – either choose from the pre-set values, or choose ‘specify value’ and give a particular value – press the ‘refresh plots’ button.

When you are satisfied, press one of the ‘make…’ buttons, which will write the text of the ‘look-up-table’ file into another window/tab. From there you should copy the text to a local file (or save as text).

The formats available are (a) DS9/saoimage, (b) decimal values for the fraction along the look-up-table (i.e. 0.0 to 1.0), and red/green/blue intensities (again 0.0 to 1.0), (c) the fraction along the look-up-table, and red/green/blue intensities in hex (00 to FF), (d) kvis look-up-table (in hex format, to convert to binary for use, copy to a local file and then (for Unix/Linux) use xxd -ps -r file.txt file.kf, where file.txt is the file you saved the output to, and file.kf is the binary file to write). You can reverse the output from the usual black → white to white → black if needed.

input parameters: output plots:
start colour: or value
number of rotations: or value
rotation direction:
hue parameter: or value
γ factor: or value
for above values shown to right
output files:
number of levels:
order: black → white white → black
make (a):
make (b):
make (c):
make (d): number of levels fixed at 200

This uses the PNGlib javascript library by Robert Eisele to generate png images in the browser (this works with Firefox, Safari, Chrome and Edge; I do not know about other browsers).

go to: main cubehelix page