Extended K2T measurement of video
View Patent ↗K2T measurement of video signals, regardless of video format, is determined by generating a graticule using an algorithm having a single variable that is a function of the video format for the particular video signal. The graticule is set to a normalized value of one for a range of +/−T, where T is a function of the video format. The graticule is set to a normalized value over a range of +/−(1.5T to flatBreak) according to a human vision masking model algorithm expressed as K+C/t, where K is a constant K factor, t is a function of T, and C is the single variable that is a function of the video format. The normalized value of the graticule beyond a point designated by flatBreak is a constant=K. Finally a linear curve fit between one and K+C/t over the range of +/−(T to 1.5T) sets the remaining values for the graticule.
1. A method of generating a graticule for K2T measurement of a video signal comprising the steps of:
setting the graticule to a normalized value of one for a first range from −T to +T, where T is a function of a video format for the video signal;
setting the graticule to a normalized value determined by a human vision masking model algorithm for a third range from −1.5T to −flatBreak and +1.5T to +flatBreak, flatBreak being a point beyond which the graticule has a constant normalized value; and
setting the graticule to a normalized value determined by a linear curve fit over a second range from −T to −1.5T and T to +1.5T between the first and third ranges.
2. The method as recited in claim 1 wherein the human vision masking model algorithm comprises a predicted mask of normalized values determined according to the equation: K+C/t where K is a desired K factor, t is a normalized time increment related to T, and C is a variable determined by the video format.