Smoke detecting method and device

• US 7,859,419 B2
• Filed: 04/09/2008
• Issued: 12/28/2010
• Est. Priority Date: 12/12/2006
• Status: Active Grant

• Current Assignee: Industrial Technology Research Institute
• Original Assignee: Industrial Technology Research Institute
• Inventors: Chung-Hsien, Lu, Cheng-Wei, Wang, Kun-Lin, Huang, Yu-Ren, Hsu, Shih-Hua, Chang, Hao-Ting, Chao, Shen-Kuen, Chang
• Primary Examiner(s): Nguyen; Tai T
• Application Number:
  US12/081,014
• Publication Number:
  US 20080186191A1
• Time in Patent Office: 993 Days
• Field of Search: 340/628, 340/575, 340/577, 340/578, 340/584, 340/600, 382/100, 382/103, 382/107, 382/190, 348/135, 348/169, 348/226.1
• US Class Current: 340/628
• CPC Class Codes: G06V 20/52 Surveillance or monitoring of activities, e.g. for recognising suspicious objects recognising microscopic objects G06V20/69
• CPC Class Codes: G08B 17/125 by using a video camera to detect fire or smoke

Abstract

A smoke detecting method and device are provided. The smoke detecting method and device capture a plurality of images; determine one of the plurality of images as an analyzable image when the one of the plurality of images is identified to have a moving object; analyze a chrominance variation of the analyzable image; analyze at least one of an edge blur and a flickering frequency of the analyzable image; compare at least one of analyzed results from the analyzing steps with a corresponding predetermined feature; and determine the moving object is a smoke when at least one of the analyzed results conforms to the corresponding predetermined feature.

Claims

1. A smoke detecting method, comprising:

capturing a plurality of images;

determining one of the plurality of images as an analyzable image when the one of the plurality of images is identified to have a moving object;

analyzing a chrominance variation of the analyzable image;

analyzing at least one of an edge blur and a flickering frequency of the analyzable image;

comparing at least one of analyzed results from the analyzing steps with a corresponding predetermined feature; and

determining the moving object is a smoke when at least one of the analyzed results conforms to the corresponding predetermined feature.

2. The smoke detecting method according to claim 1, further comprising actuating an alarm when the moving object is determined as the smoke.

3. The smoke detecting method according to claim 1, wherein the step of analyzing the chrominance variation of the analyzable image further comprises:

analyzing at least one variation of S, Y, U, V and I values of each pixel displaying the moving object in the analyzable image.

4. The smoke detecting method according to claim 1, wherein the step of analyzing the edge blur of the analyzable image further comprises:

detecting an edge pixel(s) in a plurality of pixels displaying the moving object in the analyzable image and analyzing a strength value variation of each of the edge pixel(s).

5. The smoke detecting method according to claim 1, wherein the step of analyzing the flickering frequency of the analyzable image further comprises:

analyzing the flickering frequency of the analyzable image by a time wavelet calculation.

6. The smoke detecting method according to claim 1 further comprising a step of:

setting a location in a background image of the plurality of images as a no-analyzing location before the step of determining one of the plurality of images as an analyzable image.

7. The smoke detecting method according to claim 1 further comprising a step of:

analyzing a centroid of the moving object and if the moving object is expanding within a predetermined time period.

8. A smoke detecting device, comprising:

an image capturing device capturing a plurality of images;

an analyzing device coupled to the image capturing device, determining one of the plurality of images as an analyzable image when the one of the plurality of images is identified to have a moving object, analyzing a chrominance variation of the analyzable image, and analyzing at least one of an edge blur and a flickering frequency of the analyzable image; and

a determining device coupled to the analyzing device for comparing at least one of analyzed results obtained from the analyzing device with a corresponding predetermined feature and determining the moving object is a smoke when at least one of the analyzed results conforms to the corresponding predetermined feature.

9. The smoke detecting device according to claim 8 further comprising an alarming device coupled to the determining device for actuating an alarm when the moving object is determined as the smoke.

10. The smoke detecting device according to claim 8, wherein the analyzing device further comprising a chrominance analyzing device analyzing at least one variation of S, Y, U, V and I values of each pixel displaying the moving object in the analyzable image.

11. The smoke detecting device according to claim 8, wherein the analyzing device further comprising at least one of:

an edge blur analyzing device detecting an edge pixel(s) in a plurality of pixels displaying the moving object in the analyzable image and calculating a strength value variation of each of the edge pixel(s); and

a flickering frequency analyzing device analyzing a flickering frequency of the analyzable image by a time wavelet calculation.

12. The smoke detecting device according to claim 8 further comprising:

a setting device setting a location in a background image of the plurality of images as a no-analyzing location before the analyzing device determining one of the plurality of images as an analyzable image.

13. The smoke detecting device according to claim 8, wherein the analyzing device further comprising:

an action analyzing device analyzing a centroid of the moving object and if the moving object is expanding within a predetermined time period.

14. The smoke detecting device according to claim 8, wherein the analyzing device is one of a computer and a digital signal processing chip.

15. A smoke detecting method, comprising:

capturing a plurality of images, the images comprising a background image and an analyzable image having a moving object;

analyzing at least one variation of S, U, V and I values of each pixel displaying the moving object in the analyzable image; and

determining if the moving object is a smoke by comparing analyzed results from the analyzing step with a corresponding predetermined feature.

16. The smoke detecting method according to claim 15, further comprising actuating an alarm when the moving object is determined as the smoke.

17. The smoke detecting method according to claim 15, wherein a combination of the analyzing step and the determining step further comprises:

analyzing an S value of the each pixel displaying the moving object in the analyzable image; and

determining the analyzed results conform to the corresponding predetermined feature when the S value of the each pixel is less than a predetermined value.

18. The smoke detecting method according to claim 15, wherein the determining step further comprises determining the analyzed results conform to the corresponding predetermined feature when the variations in an absolute value of the U value and an absolute value of the V value are negative when compared with the background image.

19. The smoke detecting method according to claim 15, wherein a combination of the analyzing step and the determining step further comprises:

calculating a difference of respective I values of the each pixel displaying the moving object between the background image and the analyzable image;

defining a first number of pixels, each of which has the difference smaller than a first predetermined value; and

determining the analyzed results conform to the corresponding predetermined feature when a ratio of the first number to a total number of the pixels displaying the moving object is larger than a second predetermined value.

20. The smoke detecting method according to claim 15, wherein the analyzing step further comprises analyzing at least one of an edge blur and a flickering frequency of the analyzable image.

21. The smoke detecting method according to claim 15, wherein the analyzing step further comprises analyzing a centroid of the moving object and if the moving object is expanding within a predetermined time period.

22. A smoke detecting device, comprising:

an image capturing device capturing a plurality of images, the images comprising a background image and an analyzable image having a moving object;

an analyzing device coupled to the image capturing device, and analyzing at least one variation of S, U, V and I values of each pixel displaying the moving object in the analyzable image;

a determining device coupled to the analyzing device for determining if the moving object is a smoke by comparing analyzed results obtained from the analyzing device with a corresponding predetermined feature.

23. The smoke detecting device according to claim 22, wherein the analyzing device further comprises a flickering frequency analyzing device analyzing a flickering frequency of the analyzable image.

24. The smoke detecting device according to claim 22, wherein the analyzing device further comprises an edge blur analyzing device analyzing an edge blur of the analyzable image.

25. The smoke detecting device according to claim 22, wherein the analyzing device further comprises an action analyzing device analyzing a centroid of the moving object and if the moving object is expanding within a predetermined time period.

26. A smoke detecting method, comprising:

capturing a plurality of images, the images comprising a background image and an analyzable image having a moving object;

analyzing an edge blur of the analyzable image, comprising;

detecting an edge pixel(s) in a plurality of pixels displaying the moving object in the analyzable image; and

analyzing a strength value variation of each of the edge pixel(s); and

determining if the moving object is a smoke by comparing analyzed results from the analyzing step with a corresponding predetermined feature.

27. The smoke detecting method according to claim 26, wherein a combination of the analyzing step and the determining step further comprises:

detecting a first number of the edge pixels;

calculating a first strength value of each edge pixel in the analyzable image and a second strength value of each corresponding pixel in the background image;

defining an edge pixel of the first number of edge pixels as an edge blur pixel when a ratio of the first strength value of the edge pixel to the second strength value of the corresponding pixel in the background image is less than a predetermined value;

defining a second number of edge blur pixels in the first number of edge pixels; and

determining the analyzed results conform to the corresponding predetermined feature when a ratio of the second number to the first number is within a predetermined range.

28. The smoke detecting method according to claim 26, wherein the analyzing step further comprises analyzing at least one of a chrominance variation and a flickering frequency of the analyzable image.

29. The smoke detecting method according to claim 26, wherein the analyzing step further comprises analyzing a centroid of the moving object and if the moving object is expanding within a predetermined time period.

30. A smoke detecting device, comprising:

an image capturing device capturing a plurality of images, the images comprising a background image and an analyzable image having a moving object;

an analyzing device coupled to the image capturing device, detecting an edge pixel(s) in a plurality of pixels displaying the moving object in the analyzable image, and analyzing a strength value variation of each of the edge pixel(s); and

a determining device coupled to the analyzing device for determining if the moving object is a smoke by comparing analyzed results obtained from the analyzing device with a corresponding predetermined feature.

31. The smoke detecting device according to claim 30, wherein the analyzing device further comprises a flickering frequency analyzing device analyzing a flickering frequency of the analyzable image.

32. The smoke detecting device according to claim 30, wherein the analyzing device further comprises a chrominance analyzing device analyzing a chrominance variation of the analyzable image.

33. The smoke detecting device according to claim 30, wherein the analyzing device further comprises an action analyzing device analyzing a centroid of the moving object and if the moving object is expanding within a predetermined time period.

34. A smoke detecting method, comprising:

capturing a plurality of images, the images comprising an analyzable image having a moving object;

analyzing a centroid of the moving object and if the moving object is expanding within a predetermined time period; and

determining if the moving object is a smoke by comparing analyzed results from the analyzing step with a corresponding predetermined feature.

35. The smoke detecting method according to claim 34, wherein the determining step determines the analyzed results conform to the corresponding predetermined feature when the centroid is moving in one of upward and downward directions within the predetermined time period while the moving object expands within the predetermined time period.

36. The smoke detecting method according to claim 34, wherein the analyzing step further comprises analyzing at least one of an edge blur and a chrominance variation of the analyzable image.

37. The smoke detecting method according to claim 34, wherein the analyzing step further comprises analyzing a flickering frequency of the analyzable image.

38. A smoke detecting device, comprising:

an image capturing device capturing a plurality of images, the images comprising an analyzable image having a moving object;

an analyzing device coupled to the image capturing device, analyzing a centroid of the moving object and if the moving object is expanding within a predetermined time period; and

a determining device coupled to the analyzing device for determining if the moving object is a smoke by comparing analyzed results obtained from the analyzing device with a corresponding predetermined feature.

39. The smoke detecting device according to claim 38, wherein the analyzing device further comprises a flickering frequency analyzing device analyzing a flickering frequency of the analyzable image.

40. The smoke detecting device according to claim 38, wherein the analyzing device further comprises at least one of an edge blur analyzing device analyzing an edge blur of the analyzable image and a chrominance analyzing device analyzing a chrominance variation of the analyzable image.