| 摘要 |
PROBLEM TO BE SOLVED: To smooth following by allowing a variation in peak hold level PH used for digital background elimination to have a desired following speed. SOLUTION: In response to original image data Dij, when a difference E=Dij-PH between the data Dij and the hold level PH to be a background level is positive, the difference is added to a rising transfer variable S. When an added value S+E becomes not less than a rising following constant A, PH is updated so as to be high and the variable S is updated into a value obtained by reducing the added value in accordance with the updated level. When a difference E=PH-Dij is positive, the difference is added to a falling transfer variable T. When an added value T+E becomes not less than a falling following constant B, PH is updated so as to be low and the variable T is updated into a value obtained by reducing the added value; or when a sum T+PH obtained by adding the variable T to PH at the time of changing a line exceeds the constant B, PH is updated so as to be low and the variable T is updated into a remaining value of a value equivalent to the reduced value. When a sum T+PH is less than the constant B, the update of PH is suspended and the variable T is updated into the sum T+PH. COPYRIGHT: (C)2004,JPO
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