Method for deriving consistent color measurements
A method for measuring a color value such as brightness or intensity of a sample which comprises: measuring color values for a plurality of color standards using a reference color measurement device to obtain a matrix Y that contains the measurements of the color standards as measured by the reference color measurement device; measuring the same plurality of color standards with a field color measurement device to obtain a matrix X that contains the measurements of the color standards as measured by the field color measurement device; calculating a color correction matrix B based upon the equation Y=BX, measuring the color value for the sample with the field color measurement device, and applying the color correction matrix B to the reading of the sample color to obtain a sample color value that approximates that sample color value that would be obtained using the reference measurement device.
1. A method for measuring a color value such as brightness or intensity of a sample which comprises:
measuring color values for a plurality of color standards using a reference color measurement device to obtain a matrix Y that contains the measurements of the color standards as measured by the reference color measurement device;
measuring the same plurality of color standards with a field color measurement device to obtain a matrix X that contains the measurements of the color standards as measured by the field color measurement device;
calculating a color correction matrix B based upon the equation Y=BX,
measuring the color value for the sample with the field color measurement device, and
applying the color correction matrix B to the reading of the sample color to obtain a sample color value that approximates that sample color value that would be obtained using the reference measurement device.
2. The method of claim 1 wherein the reference color measurement device includes calibration colors and the method includes the additional step of determining the effect of the sample on the measurement of the calibration colors.
3. The method of claim 2 wherein the field color measurement device includes at least two calibration colors and the method includes the additional step of determining the effect of the sample on the measurement of the calibration colors in the field color measurement device.
4. The method of claim 3 wherein the method includes the additional step of correcting the calibration color measurements for the effects of the sample.
5. The method of claim 4 wherein the method includes the step of correcting the sample color value based upon Equation (2) or Equation (4).
6. The method of claim 5 wherein there are two calibration colors and Equation (4) is used to correct the sample color.
7. The method of claim 6 wherein the matrix X is determined using the steps of correcting the value for each color standard reference using Equation (2) or Equation (4).
8. The method of claim 7 wherein the matrix Y is determined using the steps of correcting the value for each color standard reference using Equation (2) or Equation (4).
9. The method of claim 8 wherein the method includes the additional steps of initially adjusting the gain for each of the field and reference measurement devices.
10. The method of claim 4 wherein the step of correcting employ Equation (1).