Telepresence system for 360 degree video conferencing

• US 8,355,041 B2
• Filed: 02/14/2008
• Issued: 01/15/2013
• Est. Priority Date: 02/14/2008
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Chen, Wen-Hsiung, Buckingham, Patrik, Prasad, Chandrodaya, Miriyala, Prasad
• Primary Examiner(s): Kuntz, Curtis
• Assistant Examiner(s): ROBINSON, RYAN C
• Application Number:
  US12/031,209
• Publication Number:
  US 20090207234A1
• Time in Patent Office: 1,797 Days
• Field of Search: 348 1412- 1415, 348/36, 359/725, 375240-24029
• US Class Current: 348/14.12
• CPC Class Codes: H04N 19/124 Quantisation
• CPC Class Codes: H04N 19/154 Measured or subjectively estimated visual quality after decoding, e.g. measurement of distortion use of rate-distortion criteria H04N19/147
• CPC Class Codes: H04N 19/17 the unit being an image region, e.g. an object
• CPC Class Codes: H04N 19/61 in combination with predictive coding
• CPC Class Codes: H04N 23/698 for achieving an enlarged field of view, e.g. panoramic image capture

Abstract

Systems and methods for image processing, comprising receiving a video frame, coding a first portion of the video frame at a different quality than a second portion of the video frame, based on an optical property, and displaying the video frame.

Claims

1. A method for image processing in a videoconference, comprising:

receiving a video frame;

coding a first portion of the video frame at a different quality than a second portion of the video frame, based on an optical property wherein the optical property is an optical distortion property of a panoramic video camera, predetermined by measuring distortion of a known video frame; and

displaying the video frame.

2. The method of claim 1, wherein the video frame is received from a panoramic video camera.

3. The method of claim 1, wherein coding the first portion of the video frame at a different quality than the second portion of the video frame, based on an optical property comprises:

transforming the first and second portions of the video frame, resulting in a first and second plurality of coefficients;

quantizing the first plurality of coefficients based on a first plurality of quantization parameters; and

quantizing the second plurality of coefficients based on a second plurality of quantization parameters.

4. The method of claim 3, further comprising determining the first plurality of quantization parameters based on the optical property.

5. The method of claim 4, wherein the optical property is an optical property of a panoramic video camera.

6. The method of claim 1, wherein the optical distortion property is predetermined.

7. The method of claim 1, wherein the optical distortion property is predetermined by at least one of, measuring distortion of a known video frame at different camera focal lengths, measuring distortion of a known video frame by determining pixel resolution for a line or a group of lines, or measuring distortion of a known video frame by determining correlation coefficients between adjacent pixels.

8. The method of claim 3, wherein quantizing the first plurality of coefficients based on a first plurality of quantization parameters and quantizing the second plurality of coefficients based on a second plurality of quantization parameters comprises quantizing the first plurality of coefficients more than the second plurality of coefficients, resulting in higher quality coding of the first portion of the video frame.

9. The method of claim 3, wherein quantizing the first plurality of coefficients based on a first plurality of quantization parameters and quantizing the second plurality of coefficients based on a second plurality of quantization parameters comprises quantizing the first plurality of coefficients less than the second plurality of coefficients, resulting in lower quality coding of the first portion of the video frame.

10. A multi-point videoconferencing system comprised of:

a first point of the multi-point videoconferencing system comprised of a first camera, a first video display, and one or more first positions, wherein a video frame captured at the first point is a panoramic image;

a second point of the multi-point videoconferencing system comprised of a second camera, a second video display, one or more second positions; and

a processor operably connected with the first camera, wherein the processor is configured to code a first portion of the video frame at a different quality than a second portion of the video frame, based on an optical property;

wherein the optical property is an optical distortion property of the first video camera, predetermined by at least one of, measuring distortion of a known video frame at different camera focal lengths, measuring distortion of a known video frame by determining pixel resolution for a line or a group of lines, or measuring distortion of a known video frame by determining correlation coefficients between adjacent pixels.

11. The system of claim 10, wherein the first camera is a panoramic video camera.

12. The system of claim 10, wherein the processor is further configured to:

transform the first and second portions of the video frame, resulting in a first and second plurality of coefficients;

quantize the first plurality of coefficients based on a first plurality of quantization parameters; and

quantize the second plurality of coefficients based on a second plurality of quantization parameters.

13. The system of claim 12, wherein the processor is further configured to determine the first plurality of quantization parameters based on the optical property.

14. The system of claim 12, the processor is further configured to quantize the first plurality of coefficients more than the second plurality of coefficients, resulting in higher quality coding of the first portion of the video frame.

15. The system of claim 12, wherein the processor is further configured to quantize the first plurality of coefficients less than the second plurality of coefficients, resulting in lower quality coding of the first portion of the video frame.

16. A computer readable storage medium having computer executable instructions embodied thereon for image processing, comprising:

receiving a video frame from a video camera in a video conference;

predetermining an optical distortion property of the video camera by at least one of, measuring distortion of a known video frame at different camera focal lengths, measuring distortion of a known video frame by determining pixel resolution for a line or a group of lines, or measuring distortion of a known video frame by determining correlation coefficients between adjacent pixels;

coding a first portion of the video frame at a different quality than a second portion of the video frame, based on the optical distortion property; and

displaying the video frame.

17. The computer readable medium of claim 16, further comprising:

transforming the first and second portions of the video frame, resulting in a first and second plurality of coefficients;

quantizing the first plurality of coefficients based on a first plurality of quantization parameters; and

quantizing the second plurality of coefficients based on a second plurality of quantization parameters.