公开(公告)号：US6044204A

公开(公告)日：2000-03-28

申请号：US911400

申请日：1997-08-14

申请人： Masahiro Takamatsu ,  Masahiko Kubo ,  Kouichiro Shinohara ,  Nobuyuki Kato

发明人： Masahiro Takamatsu ,  Masahiko Kubo ,  Kouichiro Shinohara ,  Nobuyuki Kato

IPC分类号： G06K15/14 ,  H04N1/409 ,  G06K9/48

CPC分类号： H04N1/4092 ,  G06K15/14

摘要： To prevent the density of a low density part when an output image varies from the low density part to a high density part in a vertical scanning direction from being lowered without expanding an image forming apparatus or an image output device and increasing the cost, an image processing section first extracts an edge picture element of the low density part which is in contact with the high density part when an image output based upon input image data Si varies from the low density part to the high density part in the vertical scanning direction or from the high density part to the low density part in the vertical scanning direction. Next, the image processing section reads the number a of picture elements to be corrected and pixel value corrected quantity b from a look-up table based upon the low density part pixel value L and the high density part pixel value L before and after the edge picture element, corrects the pixel value of the input image data Si and sends the corrected output image data So to an image output section.

摘要翻译： 为了防止输出图像在垂直扫描方向上从低密度部分向高密度部分变化的低密度部分的浓度降低而不扩大图像形成装置或图像输出装置并增加成本，则图像 当基于输入图像数据Si输出的图像在垂直扫描方向上从低密度部分到高密度部分变化时，处理部分首先提取与高密度部分接触的低密度部分的边缘图像元素，或从 高密度部分到垂直扫描方向的低密度部分。 接下来，图像处理部分基于在边缘之前和之后的低密度部分像素值L和高密度部分像素值L从查找表读取要校正的像元数量a和像素值校正量b 校正输入图像数据Si的像素值，并将校正的输出图像数据So发送到图像输出部。