Tracking apparatus and tracking method

• US 6,323,898 B1
• Filed: 12/24/1996
• Issued: 11/27/2001
• Est. Priority Date: 12/28/1995
• Status: Expired due to Term

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Koyanagi, Masakazu, Hosonuma, Naoyasu, Tomitaka, Tadafusa, Suito, Taro
• Primary Examiner(s): Kelley, Chris
• Assistant Examiner(s): Vo, Tung
• Application Number:
  US08/772,922
• Time in Patent Office: 1,799 Days
• Field of Search: H04/N.5225, 348/151-159, 348/169-171, 348/211, 348/291, 348/170, 348/152, 250/332, 178/6.8, 701/209, 701/300, 382/107, 382/152
• US Class Current: 348/169
• CPC Class Codes: G01S 3/7864 T.V. type tracking systems

Abstract

A tracking apparatus for tracking an imaging object, includes: imaging means for imaging the imaging object; driving means for driving the imaging means to perform panning and tilting; position detection means for detecting a position of the imaging object in an image outputted from the imaging means; automatic tracking means for calculating a displacement amount between the position of the imaging object detected by the position detection means and a reference position in the image outputted from the imaging means and controlling the driving means based on the displacement amount so that the position of the imaging object may coincide with the reference position to automatically track the imaging object; and reference position setting means for setting the reference position.

Claims

1. A tracking apparatus for tracking an imaging object, comprising:

imaging means for imaging the imaging object;

driving means for driving said imaging means to perform panning and tilting;

position detection means for detecting a position of the imaging object within an image imaged by said imaging means;

reference area setting means for setting a reference area so that at least a tracking portion of said imaging object is located at a tracking position therefor within said reference area;

means for predicting a range of positions of said imaging object, said predicting means increasing the predicted range of positions if the detected position of the imaging object is in a peripheral region of the image; and

automatic tracking means for calculating a displacement amount between the detected position of the imaging object and said reference area in the image and controlling said driving means based on the displacement amount so that the tracking portion of the imaging object is automatically tracked to the tracking position, said automatic tracking means controlling said driving means based on the predicted range of positions when the position detection means does not detect the imaging object.

2. The apparatus according to claim 1,

wherein, when said imaging object is in the proximity of an edge of the image, said automatic tracking means controls said driving means to drive said imaging means at a higher rate than where said imaging object is located otherwise such that losing the imaging object to an area outside the image is prevented.

3. The apparatus according to claim 1,

wherein, said automatic tracking means controls said driving means to drive said imaging means to center said image on a pull-in area of said imaging object;

wherein, when said automatic tracking means cannot distinguish said pull-in area from other areas in the image, said automatic tracking means designates a different pull-in area based on a unique color of said imaging object not substantially found in other areas of the image.

4. A tracking method for tracking an imaging object within an image, said method comprising the steps of:

driving an imager to perform panning and tilting;

detecting a position of the imaging object in said image;

setting a reference area so that at least a tracking portion of said imaging object is located at a tracking position therefor within said reference area;

predicting a range of positions of said imaging object, increasing the predicted range of positions if the detected position of the imaging object is in a peripheral region of the image;

calculating a displacement amount between the detected position of the imaging object; and

controlling said driving based on the displacement amount so that the tracking portion of the imaging object is automatically tracked to the tracking position, said controlling of said driving being based on the predicted range of positions when the imaging object is not detected at said detecting step,

wherein the reference area is set to an arbitrary area in the image.

5. A tracking apparatus for tracking an imaging object, comprising:

imaging means for imaging the imaging object;

driving means for driving said imaging means to perform panning and tilting;

reference area setting means for predicting a range of positions and setting a reference area representing said predicted range of positions so that at least a tracking portion of said imaging object is located at one of said positions within said reference area, said reference area setting means increasing the predicted range of positions if the detected position of the imaging object is in a peripheral region of the image;

position detection means for detecting a position of the imaging object in an image imaged by said imaging means;

automatic tracking means for controlling said driving means based on the position of the imaging object detected by said position detection means to automatically track the imaging object;

discrimination means for discriminating whether the imaging object is present after a period of time in the reference area of the image imaged by said imaging means and generating a result of the discrimination; and

predictive tracking means for predicting, when said discrimination means indicates that the imaging object is not present, a range of said reference area in said image in which the imaging object may be present and controlling said driving means within the predicted range to predictively track the imaging object, wherein

said predictive tracking means predicts the range so that the position of the imaging object when said discrimination means indicates that the imaging object is not present is included in the reference area.

6. A tracking apparatus according to claim 5, wherein said predictive tracking means re-sets a size for the predicted range based on the position of the imaging object when the discrimination means indicates that the imaging object is not present in the reference area.

7. The apparatus according to claim 5,

wherein, when said imaging object disappears behind an object, said predictive tracking means decreases a size of said reference area in order to prevent unstability of tracking said imaging means to said imaging object.

8. The apparatus according to claim 5,

wherein when said imaging object is in the proximity of an edge of the image, said predictive tracking means increases a size of said reference area such that said imaging object is not lost to an area outside the image.

9. A tracking method for tracking an imaging object within an image, said method comprising the steps of:

driving an imager to perform panning and tilting;

detecting a position of the imaging object in said image;

predicting a range of positions and setting a reference area representing said predicted range of positions so that at least a tracking portion of said imaging object is located at one of said positions within said reference area, increasing the predicted range of positions if the detected position of the imaging object is in a peripheral region of the image;

controlling said driving based on the detected position of the imaging object to automatically track the imaging object;

discriminating whether the imaging object is present after a period of time in the reference area and generating a result of the discrimination;

predicting, when a result of discrimination indicates that the imaging object is not present in the reference area, a range in which the imaging object may be present; and

controlling said driving within the predicted range to predictively track the imaging object,

wherein the range is predicted so that the position of the imaging object when the result of discrimination indicates that the imaging object is not present is in the reference area.

10. A tracking apparatus for tracking an imaging object, comprising:

imaging means for imaging the imaging object;

driving means for driving said imaging means to perform panning and tilting;

position detection means for detecting a position of the imaging object within an image imaged by said imaging means;

reference area setting means for setting a reference area so that at least a portion of said imaging object is located at a tracking position therefor within said reference area;

automatic tracking means for controlling said driving means based on the detected position of the imaging object to automatically track the imaging object; and

gain setting means for setting, based on the detected position of the imaging object, a gain for driving said imaging means to perform panning and tilting,

wherein said gain setting means increases the gain if the detected position of the imaging object is in a peripheral region of the image, and

wherein said automatic tracking means controls said driving means based on the gain.

11. A tracking method for tracking an imaging object within an image imaged by an imager, said method comprising the steps of:

driving said imager to perform panning and tilting;

detecting a position of the imaging object;

setting a reference area so that at least a portion of said imaging object is located at a tracking position therefor within said reference area; and

controlling said driving based on the detected position of the imaging object to automatically track the imaging object,

wherein the imager is driven with a gain that is set based on the detected position of the imaging object,

wherein the gain is increased if the detected position of the imaging object is in a peripheral region of the image, and

wherein said step of controlling controls said driving based on the gain.

12. A tracking apparatus for tracking an imaging object, comprising:

imaging means for imaging the imaging object;

driving means for driving said imaging means to perform panning and tilting;

position detection means for detecting a position of the imaging object within an image imaged by said imaging means;

reference area setting means for predicting a range of positions and setting a reference area representing said predicted range of positions wherein said imaging object is located at one of said positions within said reference area;

automatic tracking means for calculating a displacement amount between the position of the imaging object detected by said position detection means and said reference area in the image imaged by said imaging means and controlling said driving means based on the displacement amount so that the position of the imaging object coincides with the reference area to automatically track the imaging object;

displacement amount setting means for setting a control start displacement amount and a control stop displacement amount corresponding respectively to a minimum displacement amount and a maximum displacement amount to be used as the displacement amount when said automatic tracking means controls said driving means; and

wherein said automatic tracking means controls said driving means based on the displacement amount set by said displacement amount setting means.

13. The apparatus according to claim 12,

wherein said control start displacement and control stop displacement are selected to form a dead zone outside of which is a background area whereat unsubstantial motion in said image occurs such that it is assured that said imaging object is within said dead zone.

14. A tracking method for tracking an imaging object within an image, said method comprising the steps of:

driving an imager to perform panning and tilting;

detecting a position of the imaging object in an image imaged by said imager;

predicting a range of positions and setting a reference area representing said predicted range of positions wherein said imaging object is located at one of said positions within said reference area;

calculating a displacement amount between the detected position of the imaging object and said reference area in the image;

controlling said driving based on the displacement amount so that the position of the imaging object coincides with the reference area to automatically track the imaging object; and

controlling said driving based on a control displacement amount and a control stop displacement amount corresponding respectively to a minimum displacement amount and a maximum displacement amount.

15. A tracking apparatus for tracking an imaging object, comprising:

imaging means for imaging the imaging object;

driving means for driving said imaging means to perform panning and tilting;

position detection means for detecting a position of the imaging object within an image imaged by said imaging means;

reference area setting means for setting a reference area so that at least a portion of said imaging object is located at a tracking position therefor within said reference area;

means for predicting a range of positions of said imaging object, said predicting means increasing the predicted range of positions if the detected position of the imaging object is in a peripheral region of the image;

automatic tracking means for controlling said driving means based on the detected position of the imaging object to automatically track the imaging object, said automatic tracking means controlling said driving means based on the predicted range of positions when the position detection means does not detect the imaging object; and

manual operation means for manually operating said driving means to control said reference area setting means to set said reference area,

wherein said automatic tracking means interrupts a current tracking operation to respond, when said manual operation means is manually operated, to a signal corresponding to the manual operation of said driving means.

16. A tracking method for tracking an imaging object within an image, comprising the steps of:

driving to perform panning and tilting;

detecting a position of the imaging object in an image imaged by an imaging means;

setting a reference area so that at least a portion of said imaging object is located at a tracking position therefor within said reference area;

predicting a range of positions of said imaging object, increasing the predicted range of positions if the detected position of the imaging object is in a peripheral region of the image;

controlling said driving based on the detected position of the imaging object to automatically track the imaging object, said controlling of said driving being based on the predicted range of positions when the imaging object is not detected at said detecting step; and

manually operating said driving,

wherein, when said driving is manually operated, a current tracking operation is interrupted to respond to a signal corresponding to the manual operation.

17. In a television telephone system,

a tracking apparatus for tracking an imaging object within an image imaged by an imager, said apparatus comprising:

compression coding means for compressing and coding an image signal imaged by said imager;

transmission means for transmitting the compressed image signal;

driving means for driving said imager to perform panning and tilting;

position detection means for detecting a position of the imaging object in an image imaged by said imager;

reference area setting means for setting a reference area so that at least a tracking portion of said imaging object is located at a tracking position therefor within said reference area;

means for predicting a range of positions of said imaging object, said predicting means increasing the predicted range of positions if the detected position of the imaging object is in a peripheral region of the image imaged by said imager; and

automatic tracking means for calculating a displacement amount between the detected position of the imaging object and said reference area in the image imaged by said imager and controlling said driving means based on the displacement amount so that the tracking portion of the imaging object is automatically tracked to the tracking position, said automatic tracking means controlling said driving means based on the predicted range of positions when the position detection means does not detect the imaging object.

18. In a television conference system, a tracking apparatus for tracking an imaging object within an image imaged by an imager, said apparatus comprising:

compression coding means for compressing and coding an image signal imaged by;

transmission means for transmitting the compressed image signal;

driving means for driving said imager to perform panning and tilting;

position detection means for detecting a position of the imaging object in an image imaged by said imager;

reference area setting means for setting a reference area so that at least a tracking portion of said imaging object is located at a tracking position therefor within said reference area;

means for predicting a range of positions of said imaging object, said predicting means increasing the predicted range of positions if the detected position of the imaging object is in a peripheral region of the image imaged by said imager; and

automatic tracking means for calculating a displacement amount between the detected position of the imaging object and said reference area in the image imaged by said imager and controlling said driving means based on the displacement amount so that the tracking portion of the imaging object is automatically tracked to the tracking position, said automatic tracking means controlling said driving means based on the predicted range of positions when the position detection means does not detect the imaging object.

19. In a television telephone system, a tracking apparatus for tracking an imaging object within an image imaged by an imager, said apparatus comprising:

compression coding means for compressing and coding an image signal imaged by said imager;

transmission means for transmitting the compressed image signal;

driving means for driving said imager to perform panning and tilting;

position detection means for detecting a position of the imaging object in an image imaged by said imager;

reference area setting means for predicting a range of positions and setting a reference area representing said predicted range of positions wherein said imaging object is located at one of said positions within said reference area;

automatic tracking means for calculating a displacement amount between the position of the imaging object detected by said position detection means and said reference area in the image imaged by said imager and controlling said driving means based on the displacement amount so that the position of the imaging object which coincides with the reference area is automatically tracked;

displacement amount setting means for setting a control start displacement amount and a control stop displacement amount to be used as the displacement amount corresponding respectively to a minimum displacement amount and a maximum displacement amount when said automatic tracking means controls said driving means; and

wherein said automatic tracking means controls said driving means based on the displacement amount set by said displacement amount setting means.

20. In a television conference system, a tracking apparatus for tracking an imaging object within an image imaged by an imager, said apparatus comprising:

compression coding means for compressing and coding an image signal imaged by said imager;

transmission means for transmitting the compressed image signal;

driving means for driving said imager to perform palming and tilting;

position detection means for detecting a position of the imaging object in an image imaged by said imager;

reference area setting means for predicting a range of positions and setting a reference area representing said predicted range of positions wherein said imaging object is located at one of said positions within said reference area;

automatic tracking means for calculating a displacement amount between the position of the imaging object detected by said position detection means and said reference in the image imaged by said imager and controlling said driving means based on the displacement amount so that the position of the imaging object which coincides with the reference area is automatically tracked;

displacement amount setting means for setting a control start displacement amount and a control stop displacement amount to be used as the displacement amount corresponding respectively to a minimum displacement amount and a maximum displacement amount when said automatic tracking means controls said driving means; and

wherein said automatic tracking means controls said driving means based on the displacement amount set by said displacement amount setting means.