| 摘要 |
<p>PURPOSE:To reduce a prediction error and to attain compression coding with higher picture quality by thinning signals by a half with an thinning means so as to attain offset for 2 lines and offset for a field and using a prediction coding means so as to apply inter-field prediction coding. CONSTITUTION:A switch 24 is used to thin color difference signals subjected to line sequential processing by a switch 23 by a half in the horizontal direction so that an offset is given for 2 lines at a sampling frequency fs and an offset is given for each field. The color difference signal written in field memories 26, 27 is read by selecting a switch 28 at a frequency of fs/2 and the result is outputted to a subtractor 5 of a prediction differential coding (DPCM) section. The color difference signal subject to DPCM coding at the DPCM coding section 6a is outputted from an output terminal 29. An interpolation device 35 interpolates the color difference signal thinned by 1/2 in the horizontal direction and outputs the result to a switch 36. Since the distance between picture elements processed by DPCM is decreased, correlation is high and the prediction error is decreased.</p> |
