| 摘要 |
A color image processing system is described which provides more realistic hard copy color images from composite video system input signals than previously available. The image processing system includes a synchronization separator 20 which operates to separate the synchronization pulses from the analog video information supplied. The separator includes an amplifier with a pair of input terminals. The video is coupled to one of the input terminals and a feedback loop coupled between an output terminal and the other input terminal. In this manner the negative synchronization pulses may be amplified while the positive video signals are limited. The extracted sync signal is used to control an analog-to-digital converter 70. The analog video information is then converted to digital form by an analog-to-digital converter. The converter operates under control of a time base generator 100, including a programmable delay line 300, which receives synchronization pulses from the synchronization separator, and following a programmable time delay supplies a control pulse to the converter to cause it to sample the analog waveform and convert it to digital format. The generator 100 employs a delay line 300 to detect the fraction of a system clock period between the sync pulse and the next clock pulse. The specified number of clock pulses are allowed to elapse. Then the delay line 300 is used to provide the necessary further delay. Once the signal is digitized, it is converted from an additive color system to a subtractive one and enhanced before being supplied to the color plotter 8.
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