Image analysis – Applications – Robotics
Reexamination Certificate
1996-06-11
2001-08-07
Couso, Jose L. (Department: 2621)
Image analysis
Applications
Robotics
C382S154000, C348S113000, C348S119000
Reexamination Certificate
active
06272237
ABSTRACT:
BACKGROUND OF THE INVENTION
FIELD OF THE INVENTION
The present invention relates to an image processing apparatus and, more particularly, to an image processing apparatus for extracting a floor region and an obstacle region from an image taken by a camera.
In medical and welfare facilities such as hospitals and nursing homes, there is a demand for the development of robots (self-propelled carriage, automatic guided vehicle, autonomous mobile robot, etc.) which automatically carry meals, washing, etc. There is also a demand for the development of self-propelled carriages used in office buildings, schools, factories, etc. and on the road or the like.
When a robot works, it is necessary to detect an obstacle in its travel range. As a method of detecting an obstacle, detection methods using an ultrasonic sensor, an optical range sensor or the like have conventionally been proposed. These methods, however, suffer from the following problems. Since a distance is measured by the ultrasonic wave or light reflected from an object, some attitude of the surface of an object or some reflection characteristic of an object makes the measurement of a distance impossible. In addition, an ultrasonic sensor has a poor spatial resolution. On the other hand, in the case of using an optical range sensor, since a wide range is measured with a high accuracy, it is necessary to use a high-output laser, which causes an apprehension as to the safety.
In contrast, there is provided a method of detecting an obstacle from an image taken by a camera. According to this method, a part in which there is a large change in the density is extracted from the image as an obstacle. Therefore, this method is free from the above-described problems of an ultrasonic sensor or an optical range sensor.
In a conventional detection method using an image taken by a camera, however, since a part in which there is a large change in the density is extracted from an image, such a large amount of computation is necessary that it is impossible to extract an obstacle in a short time.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to eliminate the above-described problems in the related art and to provide an image processing apparatus which is capable of extracting a floor region and an obstacle region from an image taken by a camera at a high speed.
To achieve this end, in one aspect of the present invention, there is provided an image processing apparatus for extracting a floor region and an obstacle region from an image taken by a camera, comprising: an image dividing means for dividing the image into a plurality of regions; an arithmetic unit for calculating the absolute value of the difference between the density of each pixel of each region and a set density and accumulating the absolute value for each region; a floor/obstacle judging portion for judging whether a target region is a floor region or an obstacle region on the basis of the result of comparison between a set value and the accumulated value of the absolute values for all the pixels within the target region or the average value of the accumulated value obtained by dividing the accumulated value by the number of pixels; and a storage portion for storing the result of the judgement.
In another aspect of the present invention, there is provided an image processing apparatus for extracting a floor region and an obstacle region from an image taken by a camera, comprising: an image dividing means for dividing the image into a plurality of regions; an average density calculator for calculating the average density of each region by dividing the accumulated value of the densities for all pixels in each region by the number of pixels; an arithmetic unit for calculating the absolute value of the difference between the density of each pixel of each region and the average density of the corresponding region and accumulating the absolute value; a floor/obstacle judging portion for judging whether a target region is a floor region or an obstacle region on the basis of the result of comparison between a set value and the accumulated value of the absolute values for all the pixels within the target region or the average value of the accumulated value obtained by dividing the accumulated value by the number of pixels; and a storage portion for storing the result of the judgement.
Other features and advantages of the present invention will be apparent from the following description taken in conjunction with the accompanying drawings.
REFERENCES:
patent: 4868752 (1989-09-01), Fujii et al.
patent: 5307419 (1994-04-01), Tsujino et al.
patent: 5386285 (1995-01-01), Asayama
patent: 5410346 (1995-04-01), Saneyoshi et al.
patent: 5486819 (1996-01-01), Horie
patent: 5535144 (1996-07-01), Kise
patent: 63-158619 (1988-07-01), None
Couso Jose L.
Dang Duy M.
Fujitsu Limited
Staas & Halsey , LLP
LandOfFree
Image processing apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Image processing apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Image processing apparatus will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2514263