Flesh tones of reproduced images in a color television receiver are enhanced by a gated automatic tint control circuit which includes first and second color demodulators each coupled to a chrominance signal source and to a phase shift network which is in turn coupled to a reference oscillator signal source. A switching means coupled to the phase shift network is also coupled to the output of one of the color demodulators. The switching means alters the phase shift network and the phase angle of the signals applied to the demodulators from the reference oscillator signal source in accordance with the output from one of the color demodulators. The television signal also includes the usual synchronization and high voltage deflection circuitry and a DC restorer circuit couples the horizontal deflection circuitry to the switching means. Thus, flesh tone enhancement and phase shifting of the reference oscillator signals is effected upon activation of the switching means in response to an output signal from one of the color demodulators.
A dynamic enabling network is described for turning off and on a color correction network in a color television receiver. The enabling network receives and combines selected color-difference signals which are superimposed on a D.C. bias level so as to generate a first control signal whose amplitude is near a maximum when the color-difference signals are representative of fleshtone hues. A second control signal, also derived from the selected color-difference signals, is a D.C. signal whose amplitude is a function of the D.C. bias level associated with the selected color-difference signals. Both control signals are applied to a comparator for turning on the color correction circuit only when the difference in amplitude between the two control signals is indicative of hues within a selected range of fleshtones.
A color signal controlling apparatus for controlling a color signal in a color television receiver. The apparatus has a color signal modifier for modifying a color signal; and a color signal stabilizer supplied with a color signal from the color signal modifier for detecting a color reference signal in a vertical blanking period and for stabilizing the color signal with reference to the color reference signal. The apparatus further has a switching circuit for supplying a switching signal in the vertical blanking period to the color signal modifier. The switching signal prohibits the color signal modifier from modifying the color reference signal to keep the desired operation of the color signal stabilizer.
A fleshtone and tint correction detector DC coupled to at least two of the first, second, and third demodulator stages of a color television receiver provides a control signal in response to a shift in differential potential output from the demodulator stages to effect a shift in phase angle of reference signals applied in the demodulators whereby fleshtone and other color errors are reduced with a minimum deleterious effect on other colors.
A method for automatically matching the color of a printed representation of an object or swatch to that of the object or swatch itself is provided. The method includes the steps of measuring the colors of the object with a calorimeter. An object image, showing mainly the object, is produced and a representative image color is determined. From the colors of the object (as measured by a colorimeter or some other color measuring device), a representative object color is determined. Finally, the colors of the object image in the vicinity, in color space, of the representative image color are corrected to colors in the vicinity, also in color space, of the representative object color.
