Using adaptive matrix Correction Method for decreasing colour measuring systematic error in tristimulus colorimeters

In image taking colorimetry the tristimulus technique is still the practical viable method if the measuring time should be kept in limits. Due to the fact that the number of coloured glasses that are available to adjust the detector responsivity to the CIE colour matching functions (CMF) is limited and the number of the filters used in a channel can not be increased without limits to decrease the adjustment error, as this would decrease the sensitivity of the colorimeter, the systematic errors of such instruments is substantial. The systematic error could be very high in case of measuring narrowband solid state lights, for instance colour LEDs. In this paper we investigated how to reduce the systematic error drastically using an adaptive matrix-based calibration method in case of measuring colour LEDs. The matrix-based calibration techniques permit using more than four channels. This paper also shows how systematic error can be decrease by using an extra filter.