| 摘要 |
<p>A comparator (1) compares with a threshold (Sn) each value (POn) of a sequence of first values each representing the intensity of one pixel of the image to be processed, which intensity is able to vary continuously, and delivers at output a second value (PRn) relating to the same image pixel as the said first value, and representing the intensity, able only to vary discretely, of the processed image. A circuit (3) is provided for calculating the value of the threshold in response to second values (PRn-1, PRn-2,... PRn-q) relating to a plurality of previously processed pixels, and a circuit (4, 5) for randomly perturbing the calculated value of the said threshold. The device of the invention applies to the numbering of images with a view to their transmission and/or their restoration in telecopying systems. <IMAGE></p> |
