公开(公告)号：US5268773A

公开(公告)日：1993-12-07

申请号：US501802

申请日：1990-03-30

申请人： Yong-Woo Park ,  Min-Ki Yeo ,  Young-Chul Kim ,  Dong-Yool Kim ,  Hong-Jik Lee ,  Hideki Koide

发明人： Yong-Woo Park ,  Min-Ki Yeo ,  Young-Chul Kim ,  Dong-Yool Kim ,  Hong-Jik Lee ,  Hideki Koide

IPC分类号： H04N1/403 ,  H04N1/40

CPC分类号： H04N1/403

摘要： A document image signal processor of gray level for use in a facsimile. The document image signal processor establishes a local window and a broad window from document image signals scanned by a CCD image sensor. An average level and a level difference between a maximum and a minimum level of the image signals are extracted from the local window. A maximum threshold of the background of the document image is extracted from the broad window. Thus, the image signals can be binarized with an adaptive threshold. Accordingly, the inventive image signal processor provides improved image, although the document image is collected (scanned) from a material whose brightness distribution is considerably ununiform. The document image signal processor includes a line-memory for reading/writing the document image signal, a local window register for forming a local image window, a broad window register for forming a broad image window register, an address and clock generator for generating address and control clocks, and an adaptive threshold logic unit for producing black/white decision logic of the center pixel.

摘要翻译： 用于传真的灰度级文件图像信号处理器。 文件图像信号处理器从由CCD图像传感器扫描的文件图像信号建立局部窗口和宽窗口。 从本地窗口提取图像信号的最大和最小电平之间的平均电平和电平差。 从广视窗中提取文档图像的背景的最大阈值。 因此，图像信号可以用自适应阈值进行二值化。 因此，本发明的图像信号处理器提供改进的图像，尽管从其亮度分布非常不均匀的材料收集（扫描）文档图像。 文件图像信号处理器包括用于读取/写入文档图像信号的行存储器，用于形成局部图像窗口的局部窗口寄存器，用于形成宽幅图像窗口寄存器的宽窗口寄存器，用于产生地址的地址和时钟发生器 和控制时钟，以及用于产生中心像素的黑/白决定逻辑的自适应阈值逻辑单元。