FIRE DETECTION AND SMOKE DETECTION METHOD AND SYSTEM BASED ON IMAGE PROCESSING

• US 20060115154A1
• Filed: 11/16/2005
• Published: 06/01/2006
• Est. Priority Date: 11/16/2004
• Status: Active Grant

• Current Assignee: Huper Laboratories Co., Ltd.
• Original Assignee: Huper Laboratories Co., Ltd.
• Inventors: Chen, Chao-Ho
• Granted Patent: US 7,542,585 B2
• Time in Patent Office: Days
• US Class Current: 382/181
• CPC Class Codes: G08B 17/125 by using a video camera to detect fire or smoke
• CPC Class Codes: G08B 29/186 Fuzzy logic; neural networks

Abstract

Fire detection and smoke detection use an image capturing device to obtain images from a predetermined area and adopts an RGB (red, green, blue) color model based chromatic and disorder measurement for extracting fire pixels and smoke pixels. The extracted pixels are inputted to a fire detection fuzzy alarm system to generate an output of alarm information. Based on iterative checking on the growing ratio of the alarm information, a fire alarm is released accordingly.

Claims

1. A fire detection and smoke detection method based on image processing comprising following steps:

(a) capturing images of a predetermined area;

(b) detecting number of fire pixels of each image;

(c) detecting number of smoke pixels of each image;

(d) generating a value according to the number of fire pixels and the number of smoke pixels of each image; and

(e) comparing values generated from images captured within a predetermined time interval to generate a comparison result.

2. The method of claim 1 wherein step (b) comprises updating the number of fire pixels when a pixel of the image satisfies the following conditions:

R>

R_T;


R≧

G>

B; and


S≧

((255−

R)*S_T/R_T);

wherein R, G, B are red, green, blue gray levels of the pixel respectively, R_T is a threshold of the red gray level, S is saturation of the pixel, and S_T is saturation of the pixel when the red gray level of the pixel equals R_T.

3. The method of claim 1 wherein step (b) comprises updating the number of fire pixels when a pixel of the image satisfies the following conditions:

R>

R_T;


R≧

G>

B;


S≧

((255−

R)*S_T/R_T); and


I>

I_T;

wherein R, G, B are red, green, blue gray levels of the pixel respectively, R_T is a threshold of the red gray level, S is saturation of the pixel, S_T is saturation of the pixel when the red gray level of the pixel equals R_T, I is intensity of the pixel, and I_T is a threshold of the intensity of the pixel.

4. The method of claim 1 further comprising checking if a ratio of number of pixels around circumference of an object formed by fire pixels of the image and number of pixels of the object is greater than a disorder threshold.

5. The method of claim 1 wherein step (c) comprises updating the number of smoke pixels when red, green and blue gray levels of a pixel of the image are approximately equal, and intensity of the pixel is within a predetermined range.

6. The method of claim 1 further comprising checking if a ratio of number of pixels around circumference of an object formed by smoke pixels of the image and number of pixels of the object is greater than a disorder threshold.

7. The method of claim 1 further comprising determining whether the images contain a flammable object or a combustible object according to the comparison result.

8. The method of claim 7 wherein step (b) comprises updating the number of fire pixels when a pixel of the image satisfies the following conditions:

R>

R_T;


R≧

G>

B;


S≧

((255−

R)*S_T/R_T); and


I>

I_T;

wherein R, G, B are red, green, blue gray levels of the pixel respectively, R_T is a threshold of the red gray level, S is saturation of the pixel, S_T is saturation of the pixel when the red gray level of the pixel equals R_T, I is intensity of the pixel, and I_T is a threshold of the intensity of the pixel;

step (c) comprises updating the number of smoke pixels when red, green and blue gray levels of a pixel of the image are approximately equal, and intensity of the pixel is within a predetermined range;

the method further comprising;

checking if a ratio of number of pixels around circumference of an object formed by fire pixels of the image and number of pixels of the object is greater than a first disorder threshold; and

checking if a ratio of number of pixels around circumference of an object formed by smoke pixels of the image and number of pixels of the object is greater than a second disorder threshold.

9. The method of claim 1 wherein step (d) generates a value according to the number of fire pixels and the number of smoke pixels of each image by a fire alarm fuzzy system.

10. The method of claim 1 further comprising outputting an alarm.

11. A method for determining a type of an object of an image comprising a following step:

(a) checking if a ratio of number of pixels around circumference of an object formed by pixels exhibiting predetermined characteristics of an image and number of pixels of the object is greater than a disorder threshold.

12. The method of claim 11 wherein step (a) comprises checking if a ratio of number of pixels around circumference of an object formed by fire pixels of an image and number of pixels of the object is greater than a disorder threshold.

13. The method of claim 11 wherein step (a) comprises checking if a ratio of number of pixels around circumference of an object formed by smoke pixels of an image and number of pixels of the object is greater than a disorder threshold.

14. A method for determining a fire pixel of an image comprising:

checking if a pixel of the image satisfies the following conditions;

R>

R_T;


R≧

G>

B;


S≧

((255−

R)*S_T/R_T); and


I>

I_T;

wherein R, G, B are red, green, blue gray levels of the pixel respectively, R_T is a threshold of the red gray level, S is saturation of the pixel, S_T is saturation of the pixel when the red gray level of the pixel equals R_T, I is intensity of the pixel, and I_T is a threshold of the intensity of the pixel.

15. A method for determining a smoke pixel of an image comprising:

checking if red, green and blue gray levels of a pixel of the image are approximately equal; and

checking if intensity of the pixel is within a predetermined range.

17. The system of claim 15 further comprising means for outputting an alarm.

18. The system of claim 15 wherein the image capturing device is a camera.

19. The system of claim 15 wherein the image capturing device is a camcorder.

16. A fire detection and smoke detection system based on image processing comprising:

an image capturing device for capturing images of a predetermined area;

means for detecting number of fire pixels and number of smoke pixels of each image captured by the image capturing device;

a fuzzy system for generating a value according to the number of fire pixels and the number of smoke pixels of each image; and

means for comparing values generated from images captured by the image capturing device within a predetermined time interval to generate a comparison result.