Patent ID: 9500526
Filing Date: 2016-11-22
CPC Classification: G01J

Claim Text:
1. A method for measuring the color uniformity of a light spot, comprising: providing an image of the light spot by a camera or camera sensor with sensor elements, each of the sensor elements capturing a set of three or more color component values that together define a set of pixel values at said each sensor element, wherein the image includes a plurality of sets of pixel values; deriving for each of the plurality of sets of pixel values at a corresponding sensor element a first ratio between a first pair of the color component values or of values obtained therefrom in said each set and a second ratio between a second pair of the color component values or of values obtained therefrom in such set, said second pair being different from the first pair in such set, wherein said providing includes projecting light from a light source onto the light spot on a white surface and imaging said light spot onto said camera sensor; and computing by means of a mathematical relationship said values obtained from the first ratio between the first pair of the color component values in each set of pixel values at a corresponding sensor element prior to the deriving, said mathematical relationship including squares of the color component values, logarithms of the color component values, or differences between the color component values and a mean or average color component value.