×

Apparatus for binarizing images

  • US 5,200,841 A
  • Filed: 05/22/1991
  • Issued: 04/06/1993
  • Est. Priority Date: 05/25/1990
  • Status: Expired due to Fees
First Claim
Patent Images

1. 1 An image binarizing apparatus for binarizing the data item of a desired pixel among the multi-value image data items of pixels composed of plural bits, the multi-value image data items being output from an image taking device in a time series manner, said image binarizing apparatus comprising:

  • multi-value image window circuitry for obtaining said multi-value image data items in the form of two dimensions, whereby said multi-value image window circuitry cuts a two-dimensional image in a small field of vision from an image plane to be taken;

    a first binarizing circuit for binarizing said multi-value image data items in accordance with a variable threshold which is determined based on said multi-value image data items of the pixels around said desired pixel;

    a second binarizing circuit for binarizing said multi-value image data items in accordance with a predetermined threshold;

    binary image window circuitry for obtaining image data which has been binarized by said second binarizing circuit, whereby said binary image window circuitry cuts a binary two-dimensional image in a small field of vision from an image plane to be taken;

    edge detecting circuitry for comparing and collating the binary two-dimensional image data obtained by said binary image window circuitry with edge templates each having a predetermined angle, whereby said edge detecting circuitry detects whether or not the position of said desired pixel is on an edge, and outputs an edge direction in the form of edge detection data when the position of said desired pixel is on the edge;

    memory circuitry for storing two types of smoothly binarized data in addresses which are generated based not only on the multi-value image data items obtained by said multi-value image window circuitry, but also on the edge detection data which is output from said edge detecting circuitry, the two types of smoothly binarized data stored in said memory circuitry being dependent on the smooth binary image data of a pixel adjacent to said desired pixel in said edge direction, said memory circuitry outputting two types of smooth binary image data in the addresses which correspond to said multi-value image data items and said edge detection data; and

    selecting circuitry for selecting either one of the two types of smooth binary image data which are output either from said first binarizing circuit or from said memory circuitry, whereby when said edge detecting circuitry detects that an edge is not present, said selecting circuitry selects an output from said first binarizing circuit, while on the contrary, when said edge detecting circuitry detects that an edge is present, said selecting circuitry selects either one of the two types of smooth binary image data which are output from said memory circuitry, this selection being based on the smooth binary image data of the pixel adjacent to said desired pixel in the edge direction.

View all claims
  • 2 Assignments
Timeline View
Assignment View
    ×
    ×