Display control system for videoconference terminals

• US 6,297,846 B1
• Filed: 05/29/1997
• Issued: 10/02/2001
• Est. Priority Date: 05/30/1996
• Status: Expired due to Term

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Fujitsu Limited
• Inventors: Edanami, Takafumi
• Primary Examiner(s): Garber, Wendy R.
• Assistant Examiner(s): NGUYEN, LUONG TRUNG
• Application Number:
  US08/865,027
• Time in Patent Office: 1,587 Days
• Field of Search: 348/156, 348/15, 348/155, 348/169, 348/239, 348/240, 348/211, 348/214, 382/103, 382/203
• US Class Current: 348/239
• CPC Class Codes: G06T 9/001 Model-based coding, e.g. wire frame
• CPC Class Codes: H04N 7/142 Constructional details of the terminal equipment, e.g. arrangements of the camera and the display
• CPC Class Codes: H04N 7/148 Interfacing a video terminal to a particular transmission medium, e.g. ISDN

Abstract

A display control system for a videoconference terminal capable of displaying proper images of participants. A video camera captures wide-angle source pictures including the images of participants. The source pictures are sent to a participant position detector and image clipping unit. The participant position detector detects a participant position by examining the source pictures. Depending on the on-screen movement observed in the participant position detected by the participant position detector, the image clipping unit determines an appropriate clipping window. It clips the desired image out of the source pictures as defined by the clipping window. A screen adjustment unit adjusts the image size so that it will fit to the actual screen size.

Claims

1. A display control system for a videoconference terminal capable of displaying a proper image of a participant in a videoconference, comprising:

participant position detection means for detecting a participant position based on a wide-angle source picture provided by a camera;

image clipping means for determining a clipping window which includes the image of the participant, according to an on-screen movement of the participant position detected by said participant position detection means, and for obtaining a clipped picture by cutting an image within the clipping window out of the wide-angle source picture; and

screen adjustment means for making a size adjustment of the clipped picture obtained by said image clipping means so that the clipped picture will fit to a screen size of a video monitor unit, wherein said participant position detection means comprises

face position detection means for detecting a face position of the participant based on the wide-angle source picture provided by the camera, and

body position detection means for detecting a body position of the participant by using the face position detected by said face position detection means as a reference point.

2. The display control system according to claim 1, wherein said face position detection means comprises

facial color searching means for finding a first image portion which is likely to be the face position of the participant by comparing color data contained in the wide-angle source picture with a predetermined facial color,

motion searching means for finding a second image portion of the wide-angle source picture, which exhibits a high degree of motion, and

face position determination means for determining the face position of the participant, based on the first image portion found by said facial color searching means and the second image portion found by said motion searching means.

3. The display control system according to claim 2, wherein

said face position detection means further comprises sampling means for obtaining a sampled image by sampling the wide-angle source picture provided by the camera at predetermined pixel intervals,

said facial color searching means finds the first image portion by using said sampled image obtained by said sampling means, and

said motion searching means finds the second image portion by using said sampled image obtained by said sampling means.

4. The display control system according to claim 2, wherein said motion searching means finds the second image portion at predetermined frame intervals.

5. The display control system according to claim 2, wherein said facial color searching means compares the color data contained in the wide-angle source picture with a plurality of predetermined facial color samples so as to obtain a similarity in color space, and evaluates the likelihood to be the face position of the participant based on the similarity in color space.

6. The display control system according to claim 2, wherein said facial color searching means comprises

color bias detection means for detecting a color bias observed in an entire range of the wide-angle source picture provided by the camera, and

color bias compensation means for compensating the wide-angle source picture for the color bias detected by said color bias detection means.

7. The display control system according to claim 2, wherein said facial color searching means comprises facial color sample setting means for setting a facial color extracted from the face position as a new facial color sample for future use, when the face position is successfully determined by said face position determination means.

8. The display control system according to claim 1, wherein said body position detection means comprises

holding means for holding a predefined characteristic parameter concerning the body position of the participant,

area determination means for determining a candidate area which is likely to be the body position, based on the face position detected by said face position detection means, while referring to the predefined characteristic parameter held in said holding means,

motion detection means for detecting a motion within the candidate area determined by said area determination means, and

body position determination means for recognizing the body position when said motion detection means detected a motion at pixels as part of the candidate area.

9. A display control system for a videoconference terminal capable of displaying a proper image of a participant in a videoconference, comprising:

participant position detection means for detecting a participant position based on a wide-angle source picture provided by a camera;

image clipping means for determining a clipping window which includes the image of the participant, according to an on-screen movement of the participant position detected by said participant position detection means, and for obtaining a clipped picture by cutting an image within the clipping window out of the wide-angle source picture; and

screen adjustment means for making a size adjustment of the clipped picture obtained by said image clipping means so that the clipped picture will fit to a screen size of a video monitor unit, wherein said image clipping means comprises

movement detection means for detecting the on-screen movement of the participant position detected by said participant position detection means,

clipping window setting means, coupled to said movement detection means, for setting a large clipping window when the on-screen movement is large and a small clipping window when the on-screen movement is small, and

image extraction means for extracting, out of the wide-angle source picture provided by the camera, the image within the clipping window set by said clipping window setting means.

10. A display control system for a videoconference terminal capable of displaying a proper image of a plurality of participants in a videoconference, comprising:

face position/area detection means for detecting face positions and face areas of the plurality of participants based on a wide-angle source picture provided by a camera;

body position detection means for selecting one of the plurality of participants that exhibits the largest face area among the face areas detected by said face position/area detection means, and detecting a body position of the selected participant by using the face position thereof as a reference point;

image clipping means for determining a clipping window which includes the image of the selected participant, according to an on-screen movement of the body position detected by said body position detection means, and for obtaining a clipped picture by cutting an image within the clipping window out of the wide-angle source picture provided by the camera; and

screen adjustment means for making a size adjustment of the clipped picture obtained by said image clipping means so that the clipped picture will fit to a screen size of a video monitor unit.

11. A display control system for a videoconference terminal capable of displaying a proper image of a plurality of participants in a videoconference, comprising:

face position/area detection means for detecting face positions and face areas of the plurality of participants based on a wide-angle source picture provided by a camera;

body position detection means for selecting one of the plurality of participants that exhibits the largest face area among the face areas detected by said face position/area detection means, and detecting a body position of the selected participant by using the face position thereof as a reference point;

first image clipping means for determining a first clipping window which includes the image of the selected participant, according to an on-screen movement of the body position detected by said body position detection means, and for obtaining a first clipped picture by cutting an image within the first clipping window out of the wide-angle source picture provided by the camera;

participant position detection means for detecting individual participant positions based on a wide-angle source picture captured by a camera;

second image clipping means for determining a second clipping window which includes the images of the participants, according to on-screen movements of the individual participant positions detected by said participant position detection means, and for obtaining a second clipped picture by cutting an image within the second clipping window out of the wide-angle source picture;

clipped picture selection means for selecting one of the first and second clipped pictures; and

screen adjustment means for making a size adjustment of the selected clipped picture provided by said clipped picture selection means so that the selected clipped picture will fit to a screen size of a video monitor unit.