Method for processing gray scale images and an apparatus thereof
First Claim
1. A method for processing an original picture of a gray image composed of a target image and a background image to extract the target image separated from the background image, comprising the steps of:
- (a) obtaining a background image by processing gray levels of the original picture; and
(b) extracting the target image on the basis of a different image between the original picture and the background image obtained in step (a).
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Accused Products
Abstract
An original picture taken by an ITV camera is subject to a local maximum filter processing and, if necessary, further to a local minimum filter processing, so that a background image is formed from the original picture itself. A target image included in the original picture is extracted separated from the background image by the subtraction between the thus obtained background image and the original picture. According to the present invention, since the background image is formed on the basis of the original picture, the unevenness or change of brightness, which equally influences on both of the target image and the background image, has no influence on the accurate extraction of the target image.
95 Citations
20 Claims
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1. A method for processing an original picture of a gray image composed of a target image and a background image to extract the target image separated from the background image, comprising the steps of:
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(a) obtaining a background image by processing gray levels of the original picture; and (b) extracting the target image on the basis of a different image between the original picture and the background image obtained in step (a). - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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18. A gray image processing apparatus having a television camera for taking an original gray pictures of a predetermined area of an object, which is composed of a target image and a background image, an image memory for storing gray image data converted from the original picture of the analog form into the digital form, a processing unit in which the gray image data stored in the image memory is subject to a predetermined processing and the processed data is stored in the image memory again, and a monitor for reading out data from the image memory and displaying it thereon, whereby the target image is extracted as a contrast image separated from the background image comprising:
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at least one local maximum filter in which the gray level of a pixel in the original gray picture read out from the image memory is replaced by the maximal value of the gray levels of at least some pixels within a certain scope including the pixel, and the replaced image data is stored in the image memory again, and a local minimum filter in which the gray level of a pixel in the original gray picture read out from the image memory is replaced by the minimal value of the gray levels of at least some of pixels within a certain scope including the pixel, and the replaced image data is stored in the image memory again, whereby the background image is formed on the basis of the original picture and is stored in the image memory; and an image calculator for executing a predetermined calculation between the original picture and the background image, both being read out from the image memory, to obtain a contrast image of the target image and for returning data of the contrast image as a result of the calculation to the image memory. - View Dependent Claims (19, 20)
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Specification