| 摘要 |
<p>PURPOSE:To give compression to the picture signal to preserve both the extremely large and small information, by detecting the difference of the adjacent digital signals of the picture and then selecting and delivering part of the signal difference in accordance with the differential output. CONSTITUTION:Differential detecting circuit 11 detects difference a2-a1 of the output signal of terminal S2 out of the output signal at output terminal S1; differential circuit 12 detects difference a3-a2 of the output signal of terminal S3 out of the output signal of terminal S2; and differential circuit 13 detects difference a4-a3 between the output signals of terminals S3 and S4. The output signals of terminals S2 and S3 are transmitted to selection part 14 to deliver either one of these two signals or the signal having the mean value of these two signals in accordance with the control signal sent from recognition part 15. Then a8-a7, a9-a8 and a10-a9 are obtained via picture signals a1-a10, and thus -4, -3 and 0 are secured to feature the monotonous reduction. And 7 of signal a7 turns directly to compression signal b5, and the mean value 1.5 of signal (a8+a9), i.e., 1 turns to compression signal b6. After this, compression signals b7... are obtained in the same way. Here the extremely large value a6, i.e., 10 is reserved directly as signal b4.</p> |
