APPARATUS AND METHOD FOR SELECTING KEY FRAMES OF CLEAR FACES THROUGH A SEQUENCE OF IMAGES

• US 20080144893A1
• Filed: 12/05/2007
• Published: 06/19/2008
• Est. Priority Date: 09/14/2001
• Status: Abandoned Application

• Current Assignee: Agency For Science Technology and Research, Vislog Technology Pte Limited
• Original Assignee: Agency For Science Technology and Research, Vislog Technology Pte Limited
• Inventors: TIAN, Qi, ZHOU, Ruowei, GUO, Chun Biao
• Application Number:
  US11/950,842
• Publication Number:
  US 20080144893A1
• Time in Patent Office: Days
• US Class Current: 382/118
• CPC Class Codes: G06V 10/993 Evaluation of the quality of the acquired pattern
• CPC Class Codes: G06V 20/40 in video content extracting overlay text G06V20/62; video retrieval G06F16/70; processing of video elementary streams in video servers H04N21/234; processing of video elementary streams in video clients H04N21/44
• CPC Class Codes: G06V 40/161 Detection; Localisation; Normalisation
• CPC Class Codes: G06V 40/167 using comparisons between temporally consecutive images
• CPC Class Codes: G11B 2220/90 Tape-like record carriers
• CPC Class Codes: G11B 27/28 by using information signals recorded by the same method as the main recording G11B27/22 takes precedence
• CPC Class Codes: H04N 7/188 Capturing isolated or intermittent images triggered by the occurrence of a predetermined event, e.g. an object reaching a predetermined position signal generation from motion picture films H04N5/253

Abstract

A system for determining a key frame of an image sequence wherein the key frame includes the clearest image of the face of a person from the image sequence, the system included an image input means for receiving the image sequence of the person and a processing means for identifying the face of the person in each frame of the image sequence and then determining which frame is the clearest image of the person'"'"'s face.

Claims

1. A system for determining a key frame of an image sequence wherein said key frame includes a clearest image of a face of a person from said image sequence, said system including:

an image input means for receiving the image sequence of the person; and

a processing means for identifying the face of the person in each frame of the image sequence and then determining which frame is the clearest image of the persons face.

2. A system as claimed in claim 1 wherein said processing means analyses each frame of the image sequence including the steps of:

analysing the frame to identify a possible region for the face;

scanning the region to find the most likely position of the face; and

analysing the face to determine a clearest value.

3. A system as claimed in claim 2, wherein said processing means filters out known background information.

4. A system as claimed in claim 2, wherein pattern recognition techniques are utilized to determine the position of the face in said region.

5. A system as claimed in claim 2, wherein the clearest value is defined as a weighted sum of predefined factors.

6. A system as claimed in claim 5, wherein said clearest value is defined as:

Clearest Value=w1×

structural completeness+w2×

contrast value+w3×

symmetry value

wherein w1, w2 and w3 are predefined constants.

7. A system as claimed in claim 6, wherein pattern recognition techniques are utilized to determine whether found components conform to known face structural information, and assigning a value to said structural completeness based on the degree of conformation.

8. A system as claimed in claim 6, wherein the contrast value is derived by subtracting the lowest grey level value in the face region from the highest grey level value in the face region.

9. A system as claimed in claim 2, wherein the clearest value for each frame is compared to determine the clearest frame.

10. A system as claimed in claim 2, wherein the possible region for the face is determined by analysing each of the pixels in the frame.

11. A system as claimed in claim 2, wherein the region is scanned to identify top, bottom and sides of the person'"'"'s face.

12. A system as claimed in claim 1 further including a storage means for storing said key frames.

13. A system as claimed in claim 12, wherein said video sequence and/or further data is stored together with said key frame.

14. A system as claimed in claim 13, wherein said data includes time, date, and location.

15. A system as claimed in claim 1 further including an image capture means for capturing the image sequence of the person and forwarding said image sequence to said image input means.

16. A system as claimed in claim 15 wherein said image capture means includes a video camera.

17. A system as claimed in claim 1 wherein said key frame is processed by an image enhancement means.

18. An automatic teller machine surveillance system including a system as claimed in claim 1.

19. An automatic teller machines surveillance system as claimed in claim 18 further including a trigger means to initiate surveillance.

20. An automatic teller machine surveillance system as claimed in claim 19 wherein said trigger means is activated by detection of motion.

21. An automatic teller machine surveillance system as claimed in claim 19 wherein said trigger means is activated by said person commencing a transaction at said automatic teller machine.

22. A system as claimed in claim 1 substantially as herein before described with reference to FIGS. 2 to 9 of the accompanying drawings.