How to label shape

2 views (last 30 days)
amirul
amirul on 10 Apr 2014
Commented: amirul on 11 Apr 2014
if true
% code
endS = imread('test.jpg');
S = im2bw(S);
S2 = ~S;
imshow(S2);
S3 = bwlabel(S2);
imagesc(S3);
S4 = regionprops(S3,'MinorAxisLength','MajorAxisLength','Area','Perimeter','centroid');
for cnt = 1:length(S4)
score1(cnt) = abs(1-(S4(cnt).MajorAxisLength-S4(cnt).MinorAxisLength)...
/max([S4(cnt).MajorAxisLength,S4(cnt).MinorAxisLength]));
score2(cnt) = abs(1 - abs(pi*((mean([S4(cnt).MajorAxisLength,...
S4(cnt).MinorAxisLength]))/2)^2-S4(cnt).Area)/S4(cnt).Area);
score3(cnt) = abs(1 - abs(pi*(max([S4(cnt).MajorAxisLength,...
S4(cnt).MinorAxisLength]))-S4(cnt).Perimeter)/S4(cnt).Perimeter);
end
score = mean([score1;score2;score3]);
imshow(S2)
for cnt = 1:length(S4)
text(S4(cnt).Centroid(1),S4(cnt).Centroid(2),num2str(score(cnt)),'color','red');
end
how to label the output result, if the score is higher than 0.92, then the object will have label circle. i try using if-else statement, but couldnt get it work.can someone help me.thank you
  1 Comment
Image Analyst
Image Analyst on 11 Apr 2014
You forgot to attach test.jpg. Do that and we can run your code. Also explain what "the object will have label circle" means. Do you mean you want to plot a circle in the overlay surrounding the object, or perhaps a small circle right at the centroid. And what is being computer in that long formula for score1, scroe2, and score3? Why are there no comments whatsoever in this code? ANd why is it not properly indented so that we can read it? Did you know you can type control-a and then control-i in MATLAB to fix your indenting. Then paste into the editor window here and highlight it. THEN (not before) is when you click the {}Code button. Please fix. http://www.mathworks.com/matlabcentral/answers/13205-tutorial-how-to-format-your-question-with-markup

Sign in to comment.

Accepted Answer

Image Analyst
Image Analyst on 11 Apr 2014
% Label regions.
labeledImage = bwlabel(binaryImage);
% Measure regions.
measurements = regionprops(labeledImage, 'area', 'perimeter');
% Convert structure fields into arrays.
allAreas = [measurements.Area];
appPerimeters = [measurements.Perimeter];
% Compute circularity. 1 = perfect circle. Higher numbers = more tortuous borders.
circularities = appPerimeters.^2 ./ (4*pi*allAreas);
% Find indexes of regions that are fairly circular.
indexesOfCircular = find(circularities < 4);
labeledImage = bwlabel(binaryImage);
% Measure regions.
measurements = regionprops(labeledImage, 'area', 'perimeter');
% Extract only the circular images from the labeled image and then binarize.
circleObjects = ismember(labeledImage , indexesOfCircular) > 0
% Can relabel and measure only circular blobs if you want.
Look into the code for a fully commented image segmentation tutorial.
  1 Comment
amirul
amirul on 11 Apr 2014
S = imread('test.jpg');
S = rgb2gray ( S);
bw = edge ( S, 'sobel');
bw = bwareaopen(bw,30);
se = strel('disk',2);
bw = imclose(bw,se);
bw = imfill(bw,'holes');
imshow(S2);
S3 = bwlabel(bw);
S4 = regionprops(S3,'MinorAxisLength','MajorAxisLength','Area','Perimeter','centroid');
for cnt = 1:length(S4)
score1(cnt) = abs(1-(S4(cnt).MajorAxisLength-S4(cnt).MinorAxisLength)/max([S4(cnt).MajorAxisLength,S4(cnt).MinorAxisLength]));
% for score 1, it basically test the roundness of the object
score2(cnt) = abs(1 - abs(pi*((mean([S4(cnt).MajorAxisLength,S4(cnt).MinorAxisLength]))/2)^2-S4(cnt).Area)/S4(cnt).Area);
% for score 2 , it will test the ratio of area and the roundness
score3(cnt) = abs(1 - abs(pi*(max([S4(cnt).MajorAxisLength,S4(cnt).MinorAxisLength]))-S4(cnt).Perimeter)/S4(cnt).Perimeter);
% for score 3, it will test and give ratio of roundness and perimeter
end
score = mean([score1;score2;score3]);
% then all the 3 score will be mean to find the score.
%This score will be used to find the presence of circle object in image.
% Circle object will have certain value of score ( in this case 0.97)
imshow(S2)
for cnt = 1:length(S4)
text(S4(cnt).Centroid(1),S4(cnt).Centroid(2),num2str(score(cnt)),'color','red');
end
% so ryte now im replacing the above code with below code , but it doesnt work, it should have
% label with name circle on it, but it doesnt work, it can run, but the
% there is no output
%for cnt = 1:length(S4)
% if score > 0.95
%text(S4(cnt).Centroid(1),S4(cnt).Centroid(2),num2str( 'Circle' ),'color','red');
%else
%text(S4(cnt).Centroid(1),S4(cnt).Centroid(2),num2str( 'Not Circle'),'color','red');
%end
% end
if true
% code
end

Sign in to comment.

More Answers (0)

Categories

Find more on Image Processing Toolbox in Help Center and File Exchange

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!