| 摘要 |
Hue and saturation are modified in a composite video signal processor by detecting the phase of the chrominance signal component to determine if it possesses phase components at or near a predetermined phase angle. If such components exist, quadrature related saturation and hue modifying signals are added to the composite video signal in controlled proportions and polarities to provide a resultant composite video signal in which a specified color or range of colors is modified. The modifying signals are inhibited by a masking unit to confine the color modification to predetermined areas of the displayed color image. Specific picture locations where color changes occur are identified by substituting an AC signal within the luminance frequency band for the color modifying signals. A desaturation signal derived from the hue modifying signals is added to the composite video signal to minimize changes in saturation level of the composite video signal as hue is changed.
|
