or light sources are used in colorimetric
analysis or color
comparison of the software. For some users it might be necessary to
create or use custom illuminants.
To create a custom illuminant file, please use the following file format:
Illuminant files are ASCII text files, which usually have the file extension
*.ill. An application like notepad.exe delivered with MS-Windows might
be used to create or edit illuminant files.
The illuminant file format is described in the following:
A header block might be added optionally containing information about
the illuminant using comment lines.
Comment lines start with a # character. These lines will be ignored
Main data block
The main data block contains the self reflectance values for the particular
Each line starts with the reflectance value, followed by one or more
spaces. In the same line the wavelength is given separated by // characters.
Reflectance values might contains as many decimals as required or none.
Wavelengths must be given without any decimals as integer numbers.
The wavelength range must at least cover
values from 380-780 nm!
# Custom Illuminant File
# CIE Standard Illuminant A relative spectral power distribution 300
nm - 830 nm at 5 nm intervals
# Source A
# S(Lamda) Lamda