Image analysis – Image transformation or preprocessing – Measuring image properties
Reexamination Certificate
2001-02-21
2004-12-07
Mehta, Bhavesh M (Department: 2625)
Image analysis
Image transformation or preprocessing
Measuring image properties
C345S157000
Reexamination Certificate
active
06829394
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a system and method of pointed position detection, a presentation system, and also a program.
2. Description of Related Art
In a presentation system that makes use of a projector or the like, it is necessary to detect the position of a pointer implemented by a pointer implement. In such a case, it is important to accurately detect the pointed position without having to use a special pointer implement or the like.
Various techniques are being investigated, such as one in which auxiliary illumination such as infrared light is used, the shadow of a pointer implement that is cast by this infrared light is imaged by a CCD camera or the like, and detection of the position of this pointer is based on an imaging signal therefrom. A particular problem in such a case concerns the low detection sensitivity with respect to an image formed by infrared light that is taken by the CCD camera. A CCD camera has a narrower dynamic range for infrared light than for usual visible light. It is therefore unable to pick up an infrared image efficiently. This is considered to be one cause leading to the reduction in position detection accuracy.
SUMMARY OF THE INVENTION
The present invention was devised in the light of the above described technical problem and has as an objective thereof the provision of a system and method of pointed position detection, a presentation system, and also a program for accurate pointed position detection based on an infrared image or the like.
(1) In order to solve the above described technical problem, a pointed position detection system in accordance with the present invention comprises:
image pick-up means which picks up an image of an image display region; and
position detection means which detects a position that is pointed by a pointing image within the image display region, based on image information obtained by the image pick-up means;
wherein the position detection means comprises:
movement detection means which detects movement of the pointing image; and
pointed position detection means which detects the pointed position of the pointing image when movement of the pointing image has halted.
(2) According to the present invention, there is provided a pointed position detection system comprising:
image pick-up section which picks up an image of an image display region; and
position detection section which detects a position that is pointed by a pointing image within the image display region, based on image information obtained by the image pick-up section;
wherein the position detection section comprises:
movement detection section which detects movement of the pointing image; and
pointed position detection section which detects the pointed position of the pointing image when movement of the pointing image has halted.
(3) A presentation system in accordance with the present invention comprises display means which display an image in the image display region, and the above-described pointed position detection system to detect the pointed position of the pointing image.
(4) According to the present invention, there is provided a computer-usable program for implementing a presentation system, the program that is embodied on an information storage medium or in a carrier wave, further implementing on a computer:
means for causing image pick-up means to pick up an image of an image display region; and
position detection means which detects a position that is pointed by a pointing image within the image display region, based on image information obtained by the image pick-up means;
wherein the position detection means comprises:
movement detection means which detects movement of the pointing image; and
pointed position detection means which detects the pointed position of the pointing image when movement of the pointing image has halted.
(5) A pointed position detection method in accordance with the present invention comprises:
an image picking-up step of picking up an image of an image display region; and
a position detection step of detecting a position that is pointed by a pointing image within the image display region, based on image information obtained in the image picking-up step;
wherein the position detection step comprises:
a step of detecting movement of the pointing image; and
a step of detecting the pointed position of the pointing image when movement of the pointing image has halted.
This aspect of the present invention makes it possible to perform accurate position detection by boosting the S/N ratio of the captured image, even if it is assumed that the image pick-up means has a bad S/N ratio, by using a configuration by which movement of the pointing image is detected and a still image of the pointing image is captured after confirmation that the movement has halted, then pointed position detection is based on the captured still image.
(6) In each of the above pointed position detection system, presentation system, and program, the image pick-up means may pick up an infrared image of the image display region which is formed by infrared light;
the movement detection means may detect movement of the pointing image based on the infrared image formed by infrared light; and
the pointed position detection means may detect the pointed position of the pointing image based on the infrared image formed by infrared light.
This makes it possible to separate the projected background image and the pointing image efficiently, thus enabling efficient movement detection with a simple configuration, when the light for an image is projected from the projector onto the image display region, by way of example.
It also makes it possible to perform position detection based on an infrared image without using any special means, thus simplifying the system configuration.
Note that infrared light generally ranges in wave-length from 700 nm to 1 mm.
(7) In each of the pointed position detection system, presentation system, and program,
the image pick-up means may pick up an infrared image of the image display region formed by infrared light and a visible-light image of the image display region formed by visible light;
the movement detection means may detect movement of the pointing image based on the infrared image formed by infrared light; and
the pointed position detection means may detect the pointed position of the pointing image based on the visible-light image formed by visible light.
This makes it possible to separate the projected background image and the pointing image efficiently, thus enabling efficient movement detection with a simple configuration.
In such a case, it is preferable to provide switching between a filter for visible light and a filter for infrared light, in the light path in front of the image pick-up means.
More specifically, a shutter configuration could be enabled or infrared and visible-light filters could be provided to cover the two halves of a circular filter mechanism, where the mechanism is switched by a motor drive.
If the image pick-up means is implemented by a CCD camera, by way of example, this aspect of the invention makes it possible to provide imaging by a single CCD camera, instead of a plurality of CCD cameras for taking images formed by visible light and infrared light.
This capturing of a still image as an image formed by visible light during position detection enables an increase in the dynamic range of the thus-captured image, thus making it possible to achieve accurate position detection that is not affected by ambient noise around the pointing image.
Note that the visible light generally ranges in wavelength from 400 nm to 700 nm.
(8) In each of the above pointed position detection system, presentation system, and program,
the image pick-up means may pick up an infrared image of the image display region formed by infrared light and a visible-light image of the image display region formed by visible light;
the movement detection means may detect movement of the pointing image based on the visible-light image formed by visible light; and
the pointed
Mehta Bhavesh M
Oliff & Berridg,e PLC
Patel Kanji
Seiko Epson Corporation
LandOfFree
System and method of pointed position detection,... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with System and method of pointed position detection,..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and System and method of pointed position detection,... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3293033