METHODS AND APPARATUS TO SELECTIVELY REDUCE STREAMING BANDWIDTH CONSUMPTION

• US 20080240239A1
• Filed: 04/02/2008
• Published: 10/02/2008
• Est. Priority Date: 04/02/2007
• Status: Abandoned Application

• Current Assignee: Raytheon Company (Rtx Corporation)
• Original Assignee: Raytheon Company (Rtx Corporation)
• Inventors: Stuart, David A.
• Application Number:
  US12/061,257
• Publication Number:
  US 20080240239A1
• Time in Patent Office: Days
• US Class Current: 375/240.12
• CPC Class Codes: G06T 7/246 using feature-based methods, e.g. the tracking of corners or segments
• CPC Class Codes: G06T 9/20 Contour coding, e.g. using detection of edges
• CPC Class Codes: H04N 19/12 Selection from among a plurality of transforms or standards, e.g. selection between discrete cosine transform [DCT] and sub-band transform or selection between H.263 and H.264
• CPC Class Codes: H04N 19/137 Motion inside a coding unit, e.g. average field, frame or block difference
• CPC Class Codes: H04N 19/14 Coding unit complexity, e.g. amount of activity or edge presence estimation H04N19/146 takes precedence
• CPC Class Codes: H04N 19/172 the region being a picture, frame or field
• CPC Class Codes: H04N 19/46 Embedding additional information in the video signal during the compression process H04N19/517, H04N19/68, H04N19/70 take precedence
• CPC Class Codes: H04N 19/527 Global motion vector estimation
• CPC Class Codes: H04N 19/61 in combination with predictive coding

Abstract

Methods and apparatus to selectively transmit compressed data based upon whether a image movement threshold has been met. In one embodiment, edge map frames are transmitted during periods of camera movement. Edge maps generated from a video stream are processed to identify the periods of camera movement.

Claims

1. A method, comprising:

receiving a stream of video frames from an image device;

generating edge maps for the video frames;

populating a data structure for containing the edge maps and for storing statistics for properties of the edge maps;

examining the statistics of the edge maps to determine whether movement of the image device is greater than a movement threshold;

selecting a format of the video frames to be transmitted based upon a time-series analysis of recent ones of the video frames, including compressing the video frames if the movement threshold is exceeded, and

transmitting the compressed video frames.

2. The method according to claim 1, wherein the movement threshold corresponds to an amount of change in edge pixels of the edge maps over time.

3. The method according to claim 2, wherein edge pixel information is contained in a pixel histogram.

4. The method according to claim 1, wherein the video frame is a color frame, and further including converting the color frame to a grey scale image.

5. The method according to claim 1, wherein the video frame is a grey scale image.

6. The method according to claim 1, further including maintaining a time-ordered arrangement of the edge maps in the data structure.

7. The method according to claim 1, further including calculating statistics describing properties for time-ordered pixels of the video frames in the data structure.

8. The method according to claim 1, wherein the statistics for the time-ordered pixels in the data structure are stored in the data structure.

9. The method according to claim 6, further including analyzing the time-ordered arrangement of edge maps to detect movement of the image device.

10. The method according to claim 1, further including determining a format of the data frame to be transmitted based on whether the movement threshold is exceeded.

11. The method according to claim 6, further including compressing the edge maps for transmission when the movement threshold is detected.

12. The method according to claim 11, further including decompressing the edge map for display.

13. The method according to claim 1, further including decompressing the compressed time-ordered series of frames for display.

14. The method according to claim 1, wherein the format of the video frame is selected from color, grey scale, edge map, and hostogram.

15. The method according to claim 1, further including updating a history of the edge maps with a current frame to replace a least current edge map in the history of edge maps, wherein the history of edge maps corresponds to a selected time interval.

16. The method according to claim 1, further including generating a bit histogram for storing the edge maps for the data frames for a selected time interval, storing an analysis of a first one of the edge maps, storing an analysis from a comparison of first one of the edge maps and other ones of the edge maps in the time interval, and/or storing metrics from an analysis of the edge maps in the time interval.