gusucode.com > KLT Tracking源码程序matlab > kltTrack.m
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% PROJECT:
% KLT Tracker
%
% BY:
% Parthipan Siva
% Assignment for SD 770-7: Topics in Particle Filtering
% Systems Design Engineering
% University of Waterloo
%
% DATE/Version:
% Jan. 2007 - V 1.0
%
% Description: kltTrack.m
% Given the output of the KLT tracker code (feature list of
% tracked and new points) this function will track an object
% with the use of replaced features.
% Note it is assumed that the KLT features were started at
% startFrame that is that all features in the KLT feature
% list file for startFrame has a value > 0.
% Note ellipse as defined by h, y and angle are assumed to be
% choosen such that all KLT features withing the ellipse on
% the start frame belongs to the object of interest.
%
% References:
% http://www.ces.clemson.edu/~stb/klt/
%
% Project file list:
% drawEllipse.m
% InsidePolygon.m
% kltTrack.m
% kltTrackSIMPLE.m
% readKLTFeatureList.m
% Example1.m
% Example2.m
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% INPUTS:
% dir - the directory location where the KLT features are located
% dir2 - the directory where the pgm image for each frame is
% located
% fileStart1 - the start of a file name (not including the frame
% number) it is assumed that KLT features and image
% files have the same file nume but with extensions
% .txt and .pgm
% h - the spread in row and col directions of the ellipse
% sarounding the object (on the first frame)
% y - the center location of the object on the first frame
% startFrame - the start frame number
% endFrame - the frame number at which to end tracking
% TOL - the tollerance on the KLT featurs to use
% angle - the orientation of the ellipse sarrounding the object
% TIME_WINDOW - the duration in frames during which the KLT
% feature points must have moved
% SHOW_FIG - (optional) 1 to display figures (if movieFileName
% specified regardless of this state figure is shown)
% movieFileName - (optional) if a movie is needed specify file
% name with .avi extension
% framesPerSec - (optional) the fps for the avi, if not specified
% set to 5
%
% OUTPUTS:
% frameInfo - struct containing the info for each frame
% INDEX_OF_KEY_PTS - the key points used for
% tracking
% INDEX_OF_KEY_PTS_POT - the key points that were
% used as replacement/addition for orignal
% feature points
% y - the center location of object ellipse
% h - the row col spread of object ellipse
% ellipse - cordinates along the ellipse boundar
% used for ploting
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
function [frameInfo] = kltTrack(dir, dir2, fileStart1, h, y, startFrame, ...
endFrame, TOL, angle, TIME_WINDOW, SHOW_FIG, movieFileName, framesPerSec)
if nargin < 10
disp('Warning not enough parameters');
pause;
elseif nargin == 10
SHOW_FIG = 0;
makeMovie = 0;
elseif nargin == 11
makeMovie = 0;
elseif nargin == 12
framesPerSec = 5;
makeMovie = 1;
elseif nargin == 13
makeMovie = 1;
end
fileEnd1 = '.ppm';
fileEnd2 = '.txt';
fileEnd3 = '.pgm';
frameInfoIndex = 1;
% initialise arrays used to keep track of key points
INDEX_OF_KEY_PTS = []; % these are the set of points on the object for sure
INDEX_OF_KEY_PTS_POT = []; % these are the set of points that can potentially be on the object
% We will keep adding potential points to INDEX_OF_KEY_PTS based on its
% behaviour. Note when a point is added to INDEX_OF_KEY_PTS from
% INDEX_OF_KEY_PTS_POT it is not deleted from INDEX_OF_KEY_PTS_POT. It is
% kept as part of INDEX_OF_KEY_PTS_POT until the point stops moving for
% TIME_WINDOW number of frames, at which point it is deleted from
% INDEX_OF_KEY_PTS_POT and INDEX_OF_KEY_PTS. This is done to remove any
% KLT points that appears behind the object motion. In this case the KLT
% feature will dissapear and then reapear as the object passes over it.
% Once the object passes over it, the KLT point will be detected as a new
% feature but we don't want this to be added to the object being tracked.
% read the KLT feature points on the first frame
PointList = readKLTFeatureList([dir fileStart1 num2str(startFrame) fileEnd2]);
% get coordinates of an ellipse sarrounding the inital location of the
% object to track
ellipse = drawEllipse(y,h/2,angle);
% Find all KLT feature points within the ellipse sarounding the object
polygon = [ellipse(2,:)' ellipse(1,:)'];
for j = 1:size(PointList,1)
if (PointList(j,4)>TOL)
pt = [PointList(j,2) PointList(j,3)];
% if the KLT feature is inside the ellipse assume it is a featur to
% track.
[Inside] = InsidePolygon(polygon, pt);
if (Inside == 1)
INDEX_OF_KEY_PTS(end+1) = j;
end
end
end
if (SHOW_FIG == 1 || makeMovie == 1)
fig = figure;
end
if (makeMovie == 1)
set(fig,'DoubleBuffer','on');
mov = avifile(movieFileName,'compression','none');
end
if (SHOW_FIG == 1 || makeMovie == 1)
% read the first image
I = imread([dir2 fileStart1 num2str(startFrame) fileEnd3]);
imshow(I); hold on;
plot(PointList(INDEX_OF_KEY_PTS,2),PointList(INDEX_OF_KEY_PTS,3),'x');
plot(ellipse(2,:),ellipse(1,:));
if (makeMovie == 0)
pause(0.1);
else
F = getframe(gca);
mov = addframe(mov,F);
end
end
frameInfo(frameInfoIndex).INDEX_OF_KEY_PTS = INDEX_OF_KEY_PTS;
frameInfo(frameInfoIndex).INDEX_OF_KEY_PTS_POT = INDEX_OF_KEY_PTS_POT;
frameInfo(frameInfoIndex).y = y;
frameInfo(frameInfoIndex).h = h;
frameInfo(frameInfoIndex).ellipse = ellipse;
frameInfoIndex = frameInfoIndex + 1;
% loop through remaining figures and track the object defined in the
% ellipse.
distTimeIndex = 1;
for i = startFrame+1:endFrame
% save the previous list
PointListPrev = PointList;
% Read the KLT features for current frame
PointList = readKLTFeatureList([dir fileStart1 num2str(i) fileEnd2]);
% find the distance travelled between last frame and current frame.
% Keep the history for TIME_WINDOW number of frames.
if (distTimeIndex > TIME_WINDOW)
PastDist = PastDist(:,2:end);
PastDist(:,end+1) = sqrt((PointList(:,2)-PointListPrev(:,2)).^2 + (PointList(:,3)-PointListPrev(:,3)).^2);
else
PastDist(:,distTimeIndex) = sqrt((PointList(:,2)-PointListPrev(:,2)).^2 + (PointList(:,3)-PointListPrev(:,3)).^2);
end
distTimeIndex = distTimeIndex + 1;
% if the KLT feature is new in the current frame, set dist travelled in
% the previous frames to a large number.
locs = find(PointList(:,4)>0);
PastDist(locs,:) = 99;
% get rid of points that were not successfully traced to current frame.
% These features are lost.
j = 1;
while j<=numel(INDEX_OF_KEY_PTS)
if (PointList(INDEX_OF_KEY_PTS(j),4)~=0)
if j == 1
INDEX_OF_KEY_PTS = INDEX_OF_KEY_PTS(2:end);
elseif j == numel(INDEX_OF_KEY_PTS)
INDEX_OF_KEY_PTS = INDEX_OF_KEY_PTS(1:end-1);
else
INDEX_OF_KEY_PTS = [INDEX_OF_KEY_PTS(1:j-1) INDEX_OF_KEY_PTS(j+1:end)];
end
else
j = j + 1;
end
end
% The object size and orientation is not changed. Only it's location is
% changed. That is we are assuming only translational motion.
% % get the previous center of the ellipse as the centroid of all the KLT
% % features associated with the object in the previous frame.
% prevCenter = [sum(PointListPrev(INDEX_OF_KEY_PTS,2))/numel(INDEX_OF_KEY_PTS) ...
% sum(PointListPrev(INDEX_OF_KEY_PTS,3))/numel(INDEX_OF_KEY_PTS)];
% get the current center of the ellipse as the centroid of all the KLT
% features associated with the object in the current frame.
currCenter = [sum(PointList(INDEX_OF_KEY_PTS,2))/numel(INDEX_OF_KEY_PTS) ...
sum(PointList(INDEX_OF_KEY_PTS,3))/numel(INDEX_OF_KEY_PTS)];
% get the new ellipse boundary coordinates
ellipse = drawEllipse([currCenter(2) currCenter(1)],h/2,angle);
% Elliminate all key points not inside the ellipse in the current
% location. This needs to be removed if we assume the scale of the
% object is changing.
polygon = [ellipse(2,:)' ellipse(1,:)'];
j = 1;
while j<=numel(INDEX_OF_KEY_PTS)
pt = [PointList(INDEX_OF_KEY_PTS(j),2) PointList(INDEX_OF_KEY_PTS(j),3)];
[Inside] = InsidePolygon(polygon, pt);
if (Inside==0)
if j == 1
INDEX_OF_KEY_PTS = INDEX_OF_KEY_PTS(2:end);
elseif j == numel(INDEX_OF_KEY_PTS)
INDEX_OF_KEY_PTS = INDEX_OF_KEY_PTS(1:end-1);
else
INDEX_OF_KEY_PTS = [INDEX_OF_KEY_PTS(1:j-1) INDEX_OF_KEY_PTS(j+1:end)];
end
else
j = j + 1;
end
end
% Loop through the potential key points and remove those potential
% keypoint that were not tracked to current frame
j = 1;
while j<=numel(INDEX_OF_KEY_PTS_POT)
if (PointList(INDEX_OF_KEY_PTS_POT(j),4)~=0)
% when removing the points ensure it is also removed from
% INDEX_OF_KEY_PTS. ***** NOT SURE IF THIS IS NEEDED, THIS
% SHOULD BE REDUNDENT CODE *****
k = 1;
while (k <= numel(INDEX_OF_KEY_PTS))
if (INDEX_OF_KEY_PTS(k) == INDEX_OF_KEY_PTS_POT(j))
if k == 1
INDEX_OF_KEY_PTS = INDEX_OF_KEY_PTS(2:end);
elseif k == numel(INDEX_OF_KEY_PTS)
INDEX_OF_KEY_PTS = INDEX_OF_KEY_PTS(1:end-1);
else
INDEX_OF_KEY_PTS = [INDEX_OF_KEY_PTS(1:k-1) INDEX_OF_KEY_PTS(k+1:end)];
end
k = numel(INDEX_OF_KEY_PTS) + 1;
end
k = k + 1;
end
if j == 1
INDEX_OF_KEY_PTS_POT = INDEX_OF_KEY_PTS_POT(2:end);
elseif j == numel(INDEX_OF_KEY_PTS_POT)
INDEX_OF_KEY_PTS_POT = INDEX_OF_KEY_PTS_POT(1:end-1);
else
INDEX_OF_KEY_PTS_POT = [INDEX_OF_KEY_PTS_POT(1:j-1) INDEX_OF_KEY_PTS_POT(j+1:end)];
end
else
j = j + 1;
end
end
% check for new KLT feature points that lie inside the ellipse. If such
% a point exist inside the ellipse add it to both INDEX_OF_KEY_PTS_POT
% and INDEX_OF_KEY_PTS
for j = 1:size(PointList,1)
if (PointList(j,4) > TOL)
pt = [PointList(j,2) PointList(j,3)];
[Inside] = InsidePolygon(polygon, pt);
if (Inside == 1)
INDEX_OF_KEY_PTS_POT(end+1) = j;
% add to INDEX_OF_KEY_PTS
INDEX_OF_KEY_PTS(end+1) = j;
end
end
end
if (SHOW_FIG == 1 || makeMovie == 1)
% get current frame
I = imread([dir2 fileStart1 num2str(i) fileEnd3]);
imshow(I); hold on;
% Plot all new feature points
tempLocs = find(PointList(:,4)>TOL);
plot(PointList(tempLocs,2),PointList(tempLocs,3),'.');
% tempLocs = find(PointList(1:130,4)==0);
% plot(PointList(tempLocs,2),PointList(tempLocs,3),'r.');
% Plot all KLT features associated to object
plot(PointList(INDEX_OF_KEY_PTS,2),PointList(INDEX_OF_KEY_PTS,3),'r.','MarkerSize',5);
% Plot the ellipse
plot(ellipse(2,:),ellipse(1,:));
% Plot the center of the ellipse
plot(currCenter(1),currCenter(2),'g.');
% Plot any existing Potential feature points
if (numel(INDEX_OF_KEY_PTS_POT)>0)
plot(PointList(INDEX_OF_KEY_PTS_POT,2),PointList(INDEX_OF_KEY_PTS_POT,3),'bo','MarkerSize',5);
end
if (makeMovie == 0)
pause(0.1);
else
F = getframe(gca);
mov = addframe(mov,F);
end
end
% check for motion of all potential KLT feature points. If there are no
% motion for the past TIME_WINDOW frames removie it, because it is most
% likely an occulded KLT feature reapearing after the object moves over
% it.
if (distTimeIndex > TIME_WINDOW)
j = 1;
while j<=numel(INDEX_OF_KEY_PTS_POT)
% find the distance traved in the TIME_WINDOW as the sum of all
% displacement between two frames
totalDisplacement = PastDist(INDEX_OF_KEY_PTS_POT(j),:);
totalDisplacement = sum(totalDisplacement);
% if there are no displacement remove point from both
% INDEX_OF_KEY_PTS. ****** IDEALY WE SHOULD REMOVE IT FROM
% INDEX_OF_KEY_PTS_POT AS WELL ******
if (totalDisplacement<=0)
% plot the point in red to show it is no longer part of
% INDEX_OF_KEY_PTS
plot(PointList(INDEX_OF_KEY_PTS_POT(j),2),PointList(INDEX_OF_KEY_PTS_POT(j),3),'ro');
% remove from INDEX_OF_KEY_PTS
k = 1;
while (k <= numel(INDEX_OF_KEY_PTS))
if (INDEX_OF_KEY_PTS(k) == INDEX_OF_KEY_PTS_POT(j))
if k == 1
INDEX_OF_KEY_PTS = INDEX_OF_KEY_PTS(2:end);
elseif k == numel(INDEX_OF_KEY_PTS)
INDEX_OF_KEY_PTS = INDEX_OF_KEY_PTS(1:end-1);
else
INDEX_OF_KEY_PTS = [INDEX_OF_KEY_PTS(1:k-1) INDEX_OF_KEY_PTS(k+1:end)];
end
k = numel(INDEX_OF_KEY_PTS) + 1;
end
k = k + 1;
end
end
j = j + 1;
end
end
frameInfo(frameInfoIndex).INDEX_OF_KEY_PTS = INDEX_OF_KEY_PTS;
frameInfo(frameInfoIndex).INDEX_OF_KEY_PTS_POT = INDEX_OF_KEY_PTS_POT;
frameInfo(frameInfoIndex).y = [currCenter(2) currCenter(1)];
frameInfo(frameInfoIndex).h = h;
frameInfo(frameInfoIndex).ellipse = ellipse;
frameInfoIndex = frameInfoIndex + 1;
if (numel(INDEX_OF_KEY_PTS) == 0)
break;
end
end
if (makeMovie == 1)
mov = close(mov);
end