Target tracking algorithm in dynamic background target tracking

1. Problem description:

2. Part of the program:

% Programming By ALireza Fasih
% Email: [email protected]
% Please copy images (*.ppm) to work directory, then push F5 to view results.

clc; % clear consul
clear all; % clear all variable

% Ball Threshold Min & Max Values
th_min_ball=80;
th_max_ball=214;

% number of frams
frams = 88;

% Ball Pos initialize
old_ball_pos_x=0;
old_ball_pos_y=0;
Ball_speed_list(2,10)=0;
ball_vel_x=0;
ball_vel_y=0;

delta_x = 25;
delta_y = 25;

counter=0;
for i = 21: frams
fname=strcat('stennis.',int2str(i),'.ppm'); % Incrimental String Variable for Indexing file name

if (i<35)
delta_x=35;
delta_y=35;
else
delta_x=25;
delta_y=25;
end

if (i>80)
delta_x=30;
delta_y=15;
end

k=imread(fname); % Load Image to 'k' Matrix
k1=k;
if (old_ball_pos_x ~=0)
k1=imcrop(k,[ round(old_ball_pos_x-delta_x) round(old_ball_pos_y-delta_y) delta_x.*2 delta_y.*2 ]);
end

I=rgb2gray(k1); % Converting RGB Image to Gray Scale Image
I=im2double(I); % Converting Gray scale Image to Double type

J = medfilt2(I,[3 3]); % Median Filter , 3x3 Convolution on Image
I2 = imadjust(J); % Improve to quality of Image and adjusting contrast and brightness values
Ib = I2> 0.8627; %(220./255); % Binary Threshold for Ball

[labeled,numObjects] = bwlabel(Ib,4); % Indexing segments by binary label function
graindata = regionprops(labeled,'all'); % extracting properties from regions, 'all' means we need to all attributes
display(i); % show cycle

%---------------------- Ball Area, Filter ---------------
a_f = find( [graindata.Area] > th_min_ball & [graindata.Area] < th_max_ball); % Because Ball area is in range of 80 and 211
c1=length(a_f);
%---------------------- Ball W/H Ratio, Filter ---------------
sel=1; % default value
for j = 1 : c1

Ma=graindata(a_f(j)).MajorAxisLength;
Mi=graindata(a_f(j)).MinorAxisLength;
ratio_w_h = Ma./Mi;

if (ratio_w_h<1.7) % Ball or semi circle ratio range = ratio>0.6 & ratio<1.7
sel = a_f(j);
end
end

imshow(k); %k
hold on;

set(findobj(gca,'Type','line','Color',[0 0 1]),...
'Color','Blue',...
'LineWidth',3)

% Draw point on Ball Center
c1=graindata(sel).Centroid;

pos_list(1,i+1)=c1(1);
pos_list(2,i+1)=240-c1(2);
plot(c1(1)+old_ball_pos_x-delta_x,c1(2)+old_ball_pos_y-delta_y,'rx');

for tt=0:0.05:(2*pi)
plot(c1(1)+old_ball_pos_x-delta_x+40*cos(tt),c1(2)+old_ball_pos_y-delta_y+40*sin(tt),'g');
end

if (i>0)
ball_vel_x = (old_ball_pos_x - c1(1))./24; % 24 frame in second velocity = variation of position in delta time
ball_vel_y = (old_ball_pos_y - c1(2))./24;
end

Ball_speed_list(1,i+1)=ball_vel_x;
Ball_speed_list(2,i+1)=ball_vel_y;

if (counter>0)
old_ball_pos_x=old_ball_pos_x-delta_x+c1(1);
old_ball_pos_y=old_ball_pos_y-delta_y+c1(2);
else
old_ball_pos_x=c1(1);
old_ball_pos_y=c1(2);
end
counter=counter+1;

pause(0.1);

end