| 摘要 |
PURPOSE:To reduce the lowering of the picture quality due to the correction while keeping the brightness of the original picture image, by controlling the input signal according to the fact that the integrating value of the error is 0 or not in case the input signal is higher than the input signal level corresponding to the threshold level. CONSTITUTION:In case input Xi is 0 or more and less than threshold level Xm along with integrating error SIGMADELTAE is input Xi or more as shown in (1), Xi is set to 0 with error SIGMADELTAE changed to (SIGMADELTAE-Xi). In case error SIGMADELTAE is smaller than Xi as shown in (2), no correction is given to secure Di=Dm, i.e., Xi=Xm. And thus error DELTAE is added to error SIGMADELTAE. In case Xi is larger than Xm with SIGMADELTAE remaining as shown in (3). SIGMADELTAE must be compensated gradually. And 1 is subtracted from Xi to be delivered. And in case no SIGMADELTAE exists as shown in (4), the correction is not ncessary at all. Thus Xi is delivered directly, and SIGMADELTAE is kept at 0 as it is. |
