| 摘要 |
<p>PURPOSE:To improve the picture quality of a decoded image by providing modes to encode an input color image signal and a predictive error signal and using a time direction change in the chrominance signal component of the input image signal for switching both of these modes. CONSTITUTION:A storage circuit 9 inputs a chrominance signal component C of the input color image signal delayed for the term of one frame to a comparator circuit 2 and simultaneously inputs a luminance signal component Y of the input color image signal, chrominance signal component C and luminance component Y of the predictive error signal outputted from a subtraction circuit 1 to the circuit 2. Then, it is judged whether the input signal or the error signal is profitable for encoding by comparing the power amounts of the luminance component Y of the input signal and the luminance component Y of the error signal and comparing the hue of the chrominance component C of the input signal with the hue of the chrominance component C outputted from the circuit 9. When the input signal is profitable, the switching signal of an intra-mode is sent to the side of a transmission line as a control signal or when the error signal is profitable, the switching signal of an inter-mode is sent and simultaneously, that signal is supplied to a switching circuit 3 and a switch circuit 4 as a switch and on/off control signal.</p> |
