SURVEILLANCE SYSTEM AND SURVEILLANCE METHOD THEREOF

• US 20100033568A1
• Filed: 03/18/2009
• Published: 02/11/2010
• Est. Priority Date: 08/08/2008
• Status: Active Grant

• Current Assignee: Hon Hai Precision Industry Co., Ltd.
• Original Assignee: Hon Hai Precision Industry Co., Ltd.
• Inventors: LEE, SHIAO-WEI
• Granted Patent: US 8,248,469 B2
• Time in Patent Office: Days
• US Class Current: 348/143
• CPC Class Codes: G08B 13/1961 Movement detection not involving frame subtraction, e.g. motion detection on the basis of luminance changes in the image
• CPC Class Codes: H04N 7/183 for receiving images from a single remote source

Abstract

A method for surveillance is disclosed. Firstly, video of an area is captured. The video includes a first image and a second. Each image is subdivided into a number of subdivisions. A contrast value matrix is then calculated for each image by calculating a contrast value for each subdivision. A compared value matrix of the second image is calculated by comparing each element of the contrast value matrix associated with the current image with a corresponding element of the contrast value matrix associated with the prior image. Next, the compared value matrix is weighted using a preset weight matrix to locate the movement in the second image. Finally, the aim of capturing is adjusted based upon the location of movement.

Claims

1. A surveillance system comprising:

a video capturing unit capable of capturing video of an area, the video comprises a first image and a second image;

a detecting unit configured for subdividing each image into a plurality of subdivisions and calculating a contrast value for each subdivision to produce a contrast value matrix associated with the corresponding image;

a comparing unit configured for comparing each element of the contrast value matrix associated with the second image with a corresponding element of the contrast value matrix associated with the first image and determining a compared value matrix associated with the second image;

a calculating unit configured for weighting the compared value matrix using a preset weight value matrix to determine the location of movement in the second image; and

a controlling unit configured for adjusting aim, focus or the aim and the focus of the video capturing unit.

2. The surveillance system as claimed in claim 1, wherein the video capturing unit comprises a lens and an image sensor.

3. The surveillance system as claimed in claim 2, where in the image sensor is selected from the group consisting of a charge-coupled device and a complementary metal oxide semiconductor.

4. The surveillance system as claimed in claim 1, wherein the detecting unit counts the number of pixels whose values are greater than a predetermined value for each subdivision, and calculates the ratio of the total number of pixels to the counted number for each subdivision, the calculated ratios are the contrast values of the subdivisions.

5. The surveillance system as claimed in claim 1, wherein an element of the comparing value matrix is valued as ‘

0’

if the difference between two corresponding compared elements is smaller than a predetermined threshold and otherwise is valued as ‘

1’

.

6. The surveillance system as claimed in claim 1, wherein the preset weight value matrix is:

{A₁₁;

1 A₁₂;

2 A₁₃;

1}

{A₂₁;

2 A₂₂;

4 A₂₃;

2},

{A₃₁ 1 A₃₂ 2 A₃₃ ;

1}

the calculating unit weighting a comparing value matrix C according to the following formula;

R_mn=B<sub>(m−

1)(n−

1)</sub>×

W₁₁+B<sub>(m−

1)n</sub>×

W₁₂+B<sub>(m−

1)(n+1)</sub>×

W₁₃+B<sub>m(n−

1)</sub>×

W₂₁+B_mn×

W₂₂+B_m(n+1)×

W₂₃+B<sub>(m+1)(n−

1)</sub>×

W₃₁+B_(m+1)n×

W₃₂+B_(m+1)(n+1)×

W₃₃

where m and n are natural numbers, R_mn is an element of a weighted matrix at the intersection of m line and n row, Bmn is an element of the comparing value matrix at the intersection of m line and n row.

7. The surveillance system as claimed in claim 1, wherein the controlling unit is configured to adjust the aim, focus or the aim and focus of the video capturing unit based upon the determination of the calculating unit.

8. The surveillance system as claimed in claim 7, wherein the controlling unit is capable of keeping a moving object in the captured video.

9. A surveillance method comprising:

capturing video of an area, the video comprises a first image and a second image;

subdividing each image into a plurality of subdivisions and calculating a contrast value for each subdivision;

producing a contrast value matrix for each image;

comparing each element of the contrast value matrix of the second image with a corresponding element of the contrast value matrix of the first image and thereby determining a compared value matrix associated with the second image;

weighting the compared value matrix using a preset weight matrix to determine where movement is located in the second image; and

adjusting the aim, focus or aim and focus, of capturing to include the movement.

10. A surveillance method comprising:

providing a surveillance system comprising;

a video capturing unit capable of capturing video of an area, the video comprises a first image and a second image;

a detecting unit configured for subdividing each image into a plurality of subdivisions and calculating a contrast value for each subdivision to produce a contrast value matrix associated with the corresponding image;

a comparing unit configured for comparing each element of the contrast value matrix associated with the second image with a corresponding element of the contrast value matrix associated with the first image and determining a compared value matrix associated with the second image;

a calculating unit configured for weighting the compared value matrix using a preset weight value matrix to determine the location of movement in the second image; and

a controlling unit configured for adjusting aim, focus or the aim and the focus of the video capturing unit;

capturing the video of an area using the video capturing unit;

subdividing each image into a plurality of subdivisions and calculating the contrast value for each subdivision using the detecting unit;

producing the contrast value matrix for each image using the detecting unit;

comparing each element of the contrast value matrix of the second image with a corresponding element of the contrast value matrix of the first image and thereby determining the;

weighting the compared value matrix using the preset weight matrix to determine where movement is located in the second image using the calculating unit; and

adjusting the aim, focus or aim and focus, of capturing to include the movement using the controlling unit.