Foreground detection and Blob detection

Question

Han 2018-2-22

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/384288-foreground-detection-and-blob-detection

评论： Han 2018-2-24

采纳的回答： Image Analyst

在 MATLAB Online 中打开

Hi all ..

I'm trying to detect white objects only, but my code detect all objects

I don't know if I'm using foreground detection right or I sholud try something else !

Here is my code:

clc;
clear;
BackgroundImage = imread('frame1.jpg');
object = imread('frame2.jpg');
subplot(3,3,1);
imshow(BackgroundImage);
title('Background Frame 1');
subplot(3,3,2);
imshow(object);
title('Frame 2');
ga = rgb2gray(object);
BW = im2bw(ga);
subplot(3,3,3);
imshow(BW)
title('convert im2bw');
gb = rgb2gray(BackgroundImage);
foregroundDetector = vision.ForegroundDetector('InitialVariance',(30/255)^2);
foreground = step(foregroundDetector, gb);
subplot(3,3,4);
imshow(foreground);
title('foreground frame 1');
foreground1 = step(foregroundDetector, ga);
subplot(3,3,5);
imshow(foreground1);
title('foreground frame 2');
BlobAnalysis = vision.BlobAnalysis('MinimumBlobArea',100,'MaximumBlobArea',50000);
[area,centroid,bbox] = step(BlobAnalysis,foreground1);
Ishape = insertShape(object,'rectangle',bbox,'Color', 'green','Linewidth',6);
subplot(3,3,6);
imshow(Ishape);
title('Detect');
subplot(3,3,7);
title('Histogram');
[row , col ] = size (bbox);
for i =1 : row
 x = bbox(i,1);
 y =bbox(i,2);
 w=bbox(i,3);
 h=bbox(i,4);
TestImage = object(y :(y+h),x:(x+w), :);
r = TestImage(:,:,1);
g = TestImage(:,:,2);
b = TestImage(:,:,3);
histogram2(r,g,'DisplayStyle','tile','ShowEmptyBins','on', ...
    'XBinLimits',[0 255],'YBinLimits',[0 255]);
histogram(r,'BinMethod','integers','FaceColor','r','EdgeAlpha',0,'FaceAlpha',1)
hold on
histogram(g,'BinMethod','integers','FaceColor','g','EdgeAlpha',0,'FaceAlpha',0.7)
histogram(b,'BinMethod','integers','FaceColor','b','EdgeAlpha',0,'FaceAlpha',0.7)
xlabel('RGB value')
ylabel('Frequency')
title('Color Histogram')
xlim([0 257])
thresholding =128;
rth=graythresh(TestImage(:,:,1))*255
gth=graythresh(TestImage(:,:,2))*255
bth=graythresh(TestImage(:,:,3))*255
if ( rth*gth*bth >= thresholding )
msgbox('Alarm it is white !');
load gong.mat;
 while ( rth*gth*bth >= thresholding)%endless loop
     sound(y);
     lastTime = clock;
     while etime(clock, lastTime) < 5
        pause(0.03);
     end
    break;
 end
else
    msgbox('ok');
end
clear TestImage;
end

Here is the RESULT ! :

3 个评论
显示 1更早的评论隐藏 1更早的评论

Han 2018-2-23

I attach the two images

I want to detect white object after using foreground detection (Background subtraction)

Thank you

Han 2018-2-24

Should I use something other than Foreground detection?

Can you please advise me?

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Image Analyst 2018-2-23

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/384288-foreground-detection-and-blob-detection#answer_306719

在 MATLAB Online 中打开

Try just comparing:

foregroundFrame2 = frame2 > backgroundFrame2;

4 个评论
显示 2更早的评论隐藏 2更早的评论

Image Analyst 2018-2-24

在 MATLAB Online 中打开

Try this:

BackgroundImage = imread('frame1.jpg');
object = imread('frame2.jpg');
subplot(3,3,1);
imshow(BackgroundImage);
title('Background Frame 1');
subplot(3,3,2);
imshow(object);
title('Frame 2');
foregroundFrame2 = object > BackgroundImage;
if ndims(foregroundFrame2) > 1
  % Convert from color to 2-D logical
  foregroundFrame2 = max(foregroundFrame2, [], 3);
end
subplot(3,3,3);
imshow(foregroundFrame2);
title('foreground Frame 2');