close all;
clear all;
source=dir('*.jpg');
% ----------------------- frame size variables -----------------------
% read in 1st frame as background frame
fr=imread('000000.jpg');
fr_bw = rgb2gray(fr); % convert background to greyscale
fr_size = size(fr);
width = fr_size(2);
height = fr_size(1);
fg = zeros(height, width);
bg_bw = zeros(height, width);
% --------------------- mog variables -----------------------------------
C = 3; % number of gaussian components (typically 3-5) Cgegaosimoxing
M = 3; % number of background components,
D = 2.5; % positive deviation threshold
alpha = 0.01; % learning rate (between 0 and 1) (from paper 0.01) the background will change slowly with the time, so the mean(u)should be updated slowly.
thresh = 0.25; % foreground threshold (0.25 or 0.75 in paper)
sd_init = 6; % initial standard deviation (for new components) var = 36 in paper
w = zeros(height,width,C); % initialize weights array
mean = zeros(height,width,C); % pixel means , the u of gaosi(u,d)
sd = zeros(height,width,C); % pixel standard deviations , the d of gaosi(u,d)
u_diff = zeros(height,width,C); % difference of each pixel from mean
p = alpha/(1/C); % initial p variable (used to update mean and sd)
rank = zeros(1,C); % rank of components (w/sd)
% --------------------- initialize component means and weights -----------
pixel_depth = 8; % 8-bit resolution
pixel_range = 2^pixel_depth -1; % pixel range (# of possible values)
for i=1:height
for j=1:width
for k=1:C
mean(i,j,k) = rand*pixel_range; % means random (0-255)
w(i,j,k) = 1/C; % weights uniformly dist
sd(i,j,k) = sd_init; % initialize to sd_init
end
end
end
%--------------------- process frames -----------------------------------
for n = 1:length(source) %there will be false route line,so it only include the pictures which has the car
fr = imread(source(n).name); % read in frame
fr_bw = rgb2gray(fr); % convert frame to grayscale
% calculate difference of pixel values from mean
for m=1:C
u_diff(:,:,m) = abs(double(fr_bw) - double(mean(:,:,m)));
end
sum_x=0;
sum_y=0;
num=0;
% update gaussian components for each pixel
for i=1:height %%%%%%%%%%%%%search each pixal of one image, if it is in the C ge gaosimoxing, it is belong to the background,and undate the background.
for j=1:width %%%%%%%%%% If it is not in the C ge gaosimoxing, create a new gaosi and replace the least possible gaosi. Finally the the first several gaosi is background, and the last several is foreground
match = 0;
for k=1:C
if (abs(u_diff(i,j,k)) <= D*sd(i,j,k)) % pixel matches component
match = 1; % variable to signal component match
% update weights, mean, sd, p
w(i,j,k) = (1-alpha)*w(i,j,k) + alpha;
p = alpha/w(i,j,k);
mean(i,j,k) = (1-p)*mean(i,j,k) + p*double(fr_bw(i,j));
sd(i,j,k) = sqrt((1-p)*(sd(i,j,k)^2) + p*((double(fr_bw(i,j)) - mean(i,j,k)))^2);
else % pixel doesn't match component
w(i,j,k) = (1-alpha)*w(i,j,k); % weight slighly decreases
end
end
bg_bw(i,j)=0;
for k=1:C
bg_bw(i,j) = bg_bw(i,j)+ mean(i,j,k)*w(i,j,k);
end
% if no components match, create new component
if (match == 0)
[min_w, min_w_index] = min(w(i,j,:));
mean(i,j,min_w_index) = double(fr_bw(i,j));
sd(i,j,min_w_index) = sd_init;
end
rank = w(i,j,:)./sd(i,j,:); % calculate component rank
rank_ind = [1:1:C];
% calculate foreground
fg(i,j) = 0;
while ((match == 0)&&(k<=M))
if (abs(u_diff(i,j,rank_ind(k))) <= D*sd(i,j,rank_ind(k)))
fg(i,j) = 0; %black = 0
else
fg(i,j) = fr_bw(i,j);
sum_x=sum_x+j;
sum_y=sum_y+i;
num=num+1;
end
k = k+1;
end
end
end
%% if n==8||n==9||n==10
%% route_x=[round(sum_x/num),round(sum_x/num)];
%% route_y=[round(sum_y/num),round(sum_y/num)];
%% else
%% next_x=round(sum_x/num);
%% next_y=round(sum_y/num);
%% route_x=[route_x,next_x];
%% route_y=[route_y,next_y];
%%end
num=0;
figure(1);
%%subplot(3,1,1);
%%imshow(fr);
%%title('原始图像');
%%subplot(3,1,2);
%%imshow(uint8(bg_bw));
%%title('背景图像');
%%subplot(3,1,3);
imshow(uint8(fg));
%%hold on;
%% plot(route_x,route_y,'LineWidth',1,'Color','r');
%% title('前景图像');
disp(n);
% put frames into movie
% Mov2(n) = im2frame(uint8(bg_bw),gray); % put frames into movie
end
%%movie2avi(Mov2,'mixture_of_gaussians_background','fps',30); % save movie as avi
