Colorimetry system for display testing

1. Method for two-dimensional, spatially resolved measurement of tristimulus values of light emitted from a plurality of positions on a sample, comprising the steps of:

directing a first portion of the light to an RGB camera which produces a two-dimensional map of RGB color values;

transforming the RGB color values into first tristimulus values to produce a map of tristimulus values;

directing a second portion of the light to a colorimeter which produces second tristimulus values;

deriving a tristimulus correction by comparing the second tristimulus values with at least a subset of the first tristimulus values; and

applying the tristimulus correction to the first tristimulus values to produce a corrected map of tristimulus values.

2. Method of claim 1 , wherein the second portion of the light is emitted from a number of positions within a spot on the sample, wherein the colorimeter produces the second tristimulus values without spatial resolution.

3. Method of claim 2 , wherein the positions within the spot at least partly overlap with the positions on the sample from which the first portion of the light is emitted.

4. Method of claim 1 , wherein the colorimeter is a photoelectric colorimeter comprising a set of at least three color filters and one or more photo sensors.

5. Method of claim 1 , wherein the colorimeter is a spectral photometer.

6. Method of claim 1 , wherein the transformation for transforming the RGB color values into the first tristimulus values is derived in a prior training step, in which:

RGB color values and second tristimulus values are produced from a set of three or more training samples, and

a 3×3 transformation matrix which transforms the RGB color values into the first tristimulus values is found such that a deviation of the first tristimulus values from the second tristimulus values is minimized.

7. Method of claim 1 , wherein the tristimulus correction is derived by finding a diagonal 3×3 correction matrix which transforms the first tristimulus values of the subset of tristimulus values into corrected tristimulus values such that a deviation of the corrected tristimulus values from the second tristimulus values is minimized.

8. Method of claim 1 , wherein the sample is a matrix display.

9. Method of claim 1 , further comprising measurement of a temporal variation of a photometric parameter of the sample.

10. Imaging colorimeter system capable of two-dimensional, spatially resolved measurement of tristimulus values of light emitted from a plurality of positions on a sample, comprising:

a beam splitter splitting the light emitted from the sample into a first portion and a second portion;

an RGB camera receiving the first portion of the light and producing a two-dimensional map of RGB color values;

a controller transforming the RGB color values into first tristimulus values to produce a map of tristimulus values; and

a colorimeter receiving the second portion of the light and producing second tristimulus values,

wherein the controller is further arranged to:

derive a tristimulus correction by comparing the second tristimulus values with at least a subset of the first tristimulus values; and

apply the tristimulus correction to the first tristimulus values to produce a corrected map of tristimulus values.

11. System of claim 10 , wherein the colorimeter is a photoelectric colorimeter comprising a set of at least three color filters and one or more photo sensors.

12. System of claim 10 , wherein the colorimeter is a spectral photometer.