of fig2 described below the apparatus includes circuitry to perform these functions included in the apparatus is a circuit by which the user can increment or decrement the angle u03c6 while he is viewing the display until proper hue is attained it will be recognized that an alternate method for determining the magnitude of the vector ca is via the following relations substituting equation 3 into equations 1 and 2 yields the equations for ic and qc given by determining ca by equation 3 obviates the necessity of determining the square root of the sum of the squares of ia and qa circuitry for generating ic and qc from equations 4 and 5 will be described hereinafter with reference to fig3 the same result can also be obtained in a slightly different manner by operating on the i and q signals with single variables we know that cc 2 must equal ca 2 to maintain color saturation constant and a corrected component ic can be generated by multiplying ia by a user controlled variable u03b3 i e in order to maintain the magnitude of cc equal to the magnitude of ca the q component must be multiplied by a dependent variable e g u03b2 that is solving for u03b2 equ1 by simple trigonometric manipulation it can be shown that u03b3ia is equivalent to ca sin.