Colour Application Software

The AvaSoft-COLOUR Application has been developed to perform on-line colour measurements with a spectrometer system. It can be used for reflective colour measurements. This application provides a precise way to perform colour measurements using the basic principles and techniques defined by the International Committee on Illumination (CIE). The CIE 1976 L*a*b* colour parameters are calculated, as well as other frequently used parameters such as Hue, Chroma and X, Y, Z. 

These parameters can be displayed in a CIELAB chart or in a graph versus time.  It is also possible to save the measured L*a*b* values online to a database and use one of the products from the database as a reference colour. By comparing the measured L*a*b* values to the stored database values, colour differences (δELab, δL*, δa*, or δb*) can be measured as well. 

The colour of an object can be expressed by the CIE 1976 (L*a*b*) colour space.  L* describes the brightness of the colour. A positive value of a* describes the redness of the colour, a negative a* the greenness. Similarly, yellowness or blueness is expressed by coordinate b*, which is positive for yellow and negative for blue. The L*a*b* values are derived from the CIE tristimulus values X, Y and Z of the sample (object) and the standard illuminant tristimulus values Xn, Yn and Zn. 

The standard illuminant tristimulus values for Xn, Yn, and Zn are constant and depend only on the type of standard illuminant that has been chosen.

The CIE tristimulus values X, Y and Z of the colour of an object are obtained by multiplying the relative power P of a standard illuminant, the reflectance R (or the transmittance) of the object, and the 1931 CIE standard observer functions xλ, yλ and zλ (2 degrees angle). The integral of these products over all the wavelengths in the visible spectrum (380 to 780nm with a 5nm interval) gives the tristimulus values.

Colour Chart
The colour chart display has following features....

• Display in CIELAB chart, the actual sample colour as well as the reference colour with the corresponding δELab, δL*, δa*, or δb* values are displayed and saved as well.
• The settings for the LAB chart display can be changed, such as no graphical display of reference and sample colour in order to speed up the measurements.
• New additional option is to select the standard observer angel for 2° or 10°.
• The reference colour can be saved to and loaded from a colour database. This colour database contains next to all colour parameters a product ID and a display of the actual colour. The database can be sorted alphabetically or on either value column.
   

Time Series

The time series display has following features....

• Display in time series can be done for up to 8 channels.
• For each channel a colour parameter (L*, a*, b*, hue, C, X, Y, Z, δELab, δL*, δa*, or δb*) can be selected, also for each channel a different reference colour can be selected, enabling the use as a colour sorting.
• For each channel the time axis can be set to different scale, allowing simultaneous display of long time and short time monitoring of the same parameter.
• For each channel, the actual measured colour as well as the reference colour (if in δELab, δL*, δa*, or δb* mode) is displayed.
• The saved time series data can be loaded again and displayed with extensive zooming and dragging options.

For further information and assistance, please contact us.

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