Patent ID: 7221373
Filing Date: 2007-05-22
Classification: G01J

Abstract:
1. A method for preparing a colour chart, comprising the steps of: defining a first colour as one of black and white, the first colour having a first lightness value; defining a second colour as the other of black and white, the second colour having a second lightness value; defining a plurality of intermediate lightness values at predetermined intervals of lightness value between the first and second lightness values; defining a plurality of chroma circles at each of the intermediate lightness values, each chroma circle spanning a range of chroma values representing chromas from red to yellow to green to blue and back to red, the chroma circles at each lightness value differing from one another in hue value; populating a colour space between the first colour and the second colour by specifying a plurality of colours at each of the intermediate lightness values, wherein there are a plurality of colours for each chroma circle at each of the intermediate lightness values, the colours being specified such that each colour in the colour space is spaced from any other colour in the colour space by integral multiples of a preselected colour difference value comprising predetermined CMC values; and displaying at least one of said plurality of colours in a form that can be visually perceived by a user.