PUBLIC

MotionTrackC::MotionTrackC(RealT) MotionTrackC::Motion(DListC &,const ImageC &,const ByteImageC &,const ByteImageC &) const MotionTrackC::Track(DListC &,DListC &) const

MotionTrackC
Performs motion tracking stage
include	"amma/DERA/MotionTrack.hh"
User Level:	Default
Library:	DERARegTrack
Example:	exIndex.cc
Section:	Applications.Image Processing.DERA Small Target Detection
In Scope:	std

Comments:
MotionTrackC is responsible for performing region tracking in consecutive frames for the DERA Small Target Detection project. The purpose of the object is use motion estimation to find each region in the previous frame. If a region was detected at that position too, then the two are linked together and tracked.

The algorithm is split into two main sections:

1. The member function Motion uses a motion estimation algorithm to determine a motion vector for each region in the input list. The motion estimation algorihm that is used considers only region translation but does use a robust metric for finding image matches.
2. Track detects whether there is correspondance between regions detected in the previous frames and the predicted position of current regions in that frame. This is achieved with the following algorithm:

    list0 contains regions in previous frame
    list1 contains regions in current frame
    for each region in list1
      closest = region0
      distance = |region1.centroid + region1.motion - closest.centroid|
      for each region in list0
        nextDistance = |region1.centroid + region1.motion - region0.centroid|
        if nextDistance < distance
          distance = nextDistance
          closest = region0
      if distance < threshold
        set region1.label = closest.label
        set region1.motion = closest.centroid - region1.centroid
    

RealT _limit;

ind	Index of types of intererest.

MotionTrackC(RealT limit)

Constructor

ind	Index of types of intererest.

void Motion(DListC<RegBoundaryC> & list,const ImageC<NumLabelC> & label,const ByteImageC & scene0,const ByteImageC & scene1) const

Calculates motion for each region in list

ind	Index of types of intererest.

Estimates reverse motion, ie looks backwards from current frame to see where object was in the previous frame. Therefore, the motion vector is inverted.

const DListC<RegBoundaryC> Track(DListC<RegBoundaryC> & list0,DListC<RegBoundaryC> & list1) const

Prunes list of regions occording to their motion persistence

ind	Index of types of intererest.