On Tue, Dec 5, 2017 at 11:57 AM, Tobias Ellinghaus <[email protected]> wrote: > Am Montag, 4. Dezember 2017, 11:03:29 CET schrieb Christoph Schäfer: > [...] > >> -- - Do you know any existing open source libraries, which are converting >> spectral-data to Lab ? > > How do these values look like? How many samples per patch are given? I don't > know of such a library, but I know people who deal with these things and I > might be able to get sample code to turn into a small library.
I've recently made a new project that aims to deal with this by continuing workon other spectral color processing code. Coloritto is now a protoype CxF viewer/editor, that includes computing CIE XYZ from reflectance spectra in cxf files. My plan is towards supporting ISO17972 CxF-4 spectral characterization with tint ramps on black and white substrates - for custom spectral separation and simulation/proofing see https://gitlab.gnome.org/ok/coloritto/ for further information. The color hue match in the Freie Farbe data set is good, good enough that one can spot many errors that seem to be due to shuffling of colors or rows of colors during measurement, one such color is selected in the following screenshot : http://pippin.gimp.org/tmp/freie-farbe-bug.png and text file dump: http://pippin.gimp.org/tmp/freie-farbe.txt this screen shot uses an orthogonal projection along the L axis, the straighter the spokes the better the exact hue has been matched. PS: I plan to implement interpolation based reconstructinon of spectrum from CIE XYZ using the freie-farbe dataset as ground reference lookup table, and thus should be able to generate a new synthethic dataset based on the existing HLC_EPV_M0_V2-3.cxf that yields exact CIE Lab/lch/HCL based on these representative spectra. /Øyvind Kolås _______________________________________________ CREATE mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/create
