Patent ID: 6940597
Filing Date: 2005-09-06
Classification: G01J

Abstract:
1. A method for obtaining an approximate standard colour definition of a sample colour ( 2 ) when the sample colour is sensed under conditions which are not standard which method includes the steps of a) selecting at least twenty reference colours each having a known standard colour definition comprising previously determined known standard parameters, b) storing the standard parameters of the reference colours in a database, c) providing a template ( d) placing the template adjacent the sample colour so that the sample colour and the reference colours on the template are all visible, e) sensing the sample colour and the reference colours with quantitative colour sensing equipment ( f) expressing th non-standard and standard definitions in parameters of a common type if the are not already expressed in parameters of a common type, g) selecting a near reference colour being a reference colour which is near to the sample colour in the non-standard colour space, h) subtracting each standard parameter in the standard definition of the selected near reference colour from its corresponding non-standard parameter so as to obtain a numerical difference between the parameters of a pair of corresponding non-standard and standard parameters, which difference may be positive or negative and i) subtracting the numerical difference from the corresponding parameters of the non-standard colour definition of the sample colour whereby subtraction of the numerical differences from the corresponding parameters of the non-standard colour definition of the sample colour converts the non-standard definition into an approximate standard colour definition for the sample colour.