Motion detecting web camera system

• US 6,803,945 B1
• Filed: 09/21/1999
• Issued: 10/12/2004
• Est. Priority Date: 09/21/1999
• Status: Expired due to Term

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Needham, Bradford H.
• Primary Examiner(s): Garber, Wendy R.
• Assistant Examiner(s): MISLEH, JUSTIN P
• Application Number:
  US09/399,866
• Time in Patent Office: 1,848 Days
• Field of Search: 348/152, 348/154, 348/155, 348/207.1, 348/207.11, 348/143, 348/135, 348/699, 348/700, 348/207.99, 348/207.2, 348/211.99, 348/211.1, 348/211.3
• US Class Current: 348/207.1
• CPC Class Codes: A01K 39/00 Feeding or drinking appliances for poultry or other birds A01K31/005, A01K31/06, A01K31/17 take precedence
• CPC Class Codes: G08B 13/19602 Image analysis to detect motion of the intruder, e.g. by frame subtraction
• CPC Class Codes: G08B 13/19669 Event triggers storage or change of storage policy
• CPC Class Codes: G08B 13/19676 Temporary storage, e.g. cyclic memory, buffer storage on pre-alarm
• CPC Class Codes: H04N 23/61 based on recognised objects
• CPC Class Codes: H04N 7/183 for receiving images from a single remote source

Abstract

A camera system that includes a video camera and a processor, which periodically uploads images captured by the video camera to a web server in accordance with one of a plurality of motion detection algorithms. A first motion detection algorithm captures a current image frame when a pixel comparison between successive image frames exceeds a predetermined threshold.

Claims

1. A web camera system for uploading pictures to a web site comprising:

a video camera;

a current frame buffer to hold a current image captured by the video camera;

a previous frame buffer to hold a previous image captured prior to the current image;

a candidate buffer to hold a most recent image for periodic uploading to the web site;

logic circuitry to perform a pixel comparison between the current image and the previous image, the logic circuitry asserting a motion signal when the pixel comparison exceeds a predetermined threshold; and

the web camera system operating according to one of a plurality of modes, in a first mode of operation the current image is loaded into the candidate buffer responsive to the motion signal and in a second mode of operation the current image is loaded into the candidate buffer after a certain duration has elapsed following assertion of the motion signal.

2. The web camera system of claim 1 further comprising:

a circular buffer to store successive current images when the motion signal is asserted; and

wherein

in a third mode of operation one of the current images stored in the circular buffer is selected for loading into the candidate buffer once the motion signal has been de-asserted for a predetermined time.

3. A method of operating a web camera system comprising:

capturing a current image frame from a video camera;

asserting a motion detection signal when a pixel comparison between the current image and a previous image frame exceeds a predetermined threshold;

storing in a buffer successive image frames captured from the video camera while the motion detection signal is asserted;

de-asserting the motion detection signal when the predetermined threshold is no longer exceeded for the current image frame;

selecting from the buffer a certain one of the successive image frames as a candidate picture once the motion detection signal has been de-asserted for a certain duration; and

uploading the candidate picture to a web site.

4. The method according to claim 3 wherein the buffer is a circular buffer having a capacity to store a plurality of image frames.

5. The method according to claim 3 wherein the uploading step is performed at periodic time intervals.

6. The method according to claim 3 wherein the certain one of the successive image frames is stored a predetermined time before a last image frame is stored in the buffer prior to de-assertion of the motion detection signal.

7. The method according to claim 3 wherein the buffer is a circular buffer having a capacity to store a plurality of image frames.

8. The method according to claim 3 wherein the uploading step is performed at periodic time intervals.

9. The method according to claim 3 wherein the certain one of the successive image frames is stored a predetermined time before a last image frame is stored in the buffer prior to de-assertion of the motion detection signal.

10. A method of operating a web camera system comprising:

capturing a current image frame from a video camera;

asserting a motion detection signal when a pixel comparison between the current image and a previous image frame exceeds a predetermined threshold;

storing in a buffer successive image frames captured from the video camera while the motion detection signal is asserted;

de-asserting the motion detection signal when the predetermined threshold is no longer exceeded for the current image frame;

selecting as a candidate picture either;

(i) the current image when the motion detection signal is asserted;

(ii) the current image a first duration following de-assertion of the motion detection signal;

or

(iii) a certain one of the successive image frames from the buffer once the motion detection signal has been de-asserted for a second duration; and

uploading the candidate picture to a web site.

11. A computer-readable storage medium having a configuration that represents data and instructions that cause a processor to:

assert a motion detection signal when a pixel comparison between the current image frame captured from a video camera and a previous image frame exceeds a predetermined threshold;

store in a buffer successive image frames captured from the video camera while the motion detection signal is asserted;

de-assert the motion detection signal when the predetermined threshold is no longer exceeded for the current image frame;

select from the buffer a certain one of the successive image frames as a candidate picture once the motion detection signal has been de-asserted for a certain duration; and

upload the candidate picture to a web site.

12. The computer-readable storage medium of claim 11 wherein the medium is further configured to cause the processor to:

select as a candidate picture either;

the current image when the motion detection signal is asserted;

the current image a first duration following de-assertion of the motion detection signal;

or

a certain one of the successive image frames from the buffer once the motion detection signal has been de-asserted for a second duration.