Study on method of detecting preceding vehicle

1
Study on method of detecting preceding vehicle

• Jilin university, CHINA
• 2004 IEEE CNF

2
???

• Detecting possible object
• Measure of symmetry
• Distance Detction

3
Character of Target Vehicle

• Gray characteristics
• Boundary characteristics
• Symmetry characteristics

4
Detecting possible object

• The triangle area is called the primary area of
  interesting

5
Detecting possible object

• G(r) is the mean value of the pixel gray on r row
• rb(r) is the coordinate of pixel on right end of
  r row in the primary area of interesting
• lb(r) is the coordinate of pixel on left end of r
  row in the primary area of interesting
• g(r,c) is a gray of pixel(r,c) on r row

6
Detecting possible object
7
Detecting possible object

• P(xk) is probability of the gray value xk

8
Detecting possible object
9
Identifying area of interesting
10
Measure of symmetry

• w is the width of symmetry area
• xs is origin
• u x-xs

11
Measure of symmetry

• Energy function

• The Energy function of even function and odd
  function

12
Measure of symmetry

• Transform the even function let its mean value is
  also zero.

13
Measure of symmetry

• The range of symmetry measure is (-1,1)
• s1, it is a full symmetry
• s-1, it is no symmetry
• The symmetry depends on parameters xs and w

14
Measure of symmetry
15
Measure of symmetry
16
Measure of symmetry

• Calculate the symmetry measure about every row in
  the identifying area of interesting.
• Count the mean value of symmetry measure.

17
Distance Detction

• f is the focus of CCD camera.
• ais the incline angle of CCD camera
• h is the height of CCD camera to ground
• (x,y) is the point P projection in image plane

18
Distance Detction

• image plane coordinatemillimeter, (x,y)
• store frame coordinatepixel, (u,v)

19
Experiment for detecting preceding vehicle

• No Alg
• overall detection rate 90
• false alarm rate 13
• mean time of detecting object 82ms
• Have Alg
• verall detection rate 94
• false alarm rate 6
• mean time of detecting object 68ms

20
Experiment for distance detection