Picture recorder


PURPOSE: To effectively prevent half tone picture quality from being degraded by a texture by adopting a ground tint screen + error dispersion method and contriving a threshold pattern when a picture density code is generated. CONSTITUTION: A density code generating means 5 is equipped with a threshold value switching means 7 to switch and set various threshold values for each adjacent picture element, and a data correcting means 8 to add differential data between the picture element data of a preceding line corresponding to an attention picture element and picture elements positioning before and behind the attention picture element at least and the corresponding threshold value to the current data of the attention picture element with prescribed weighting. Further, a code setting means 9 is provided to partition the density gradation number of the corrected attention picture element by the corresponding threshold value and to define it as the picture density code. Thus, the reproduciveness of the half tone picture is more improved and the half tone picture quality is kept satisfactory. COPYRIGHT: (C)1991,JPO&Japio




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Cited By (2)

    Publication numberPublication dateAssigneeTitle
    JP-2003029181-AJanuary 29, 2003Ricoh Co Ltd, 株式会社リコーImaging device
    JP-4521800-B2August 11, 2010株式会社リコー画像形成装置