Cannot obtain all centroids from loop and shape detection
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Chanoknunt Sangsobhon
el 25 de Nov. de 2022
Comentada: Chanoknunt Sangsobhon
el 1 de Dic. de 2022
Hello. I have some problem extracting centroid from loop.
I have code for detecting some shape in images in folder.
I have 2 problems from this code.
First, I have to extract centroids from the loop, the problem is the matrix store centroid for only 1 image, when it run the next image, the new centroid was overwritten over the centroid from previous image.
Second, for detecting shape in image, the bounding box and extent were used (I modified some code from Shape Recognition to detect ellipse). The problem is both not-perfect rectangle and not-perfect circle were detected as and ellipse but I don't want it to detect rectangle.
Could anyone help me about these please? This is the code I used. Thank you in advanced!
%Specify the folder where the files live.
myFolder = 'C:\Users\---';
filePattern = fullfile(myFolder, '*.jpg');
theFiles = dir(filePattern);
for k = 1 : length(theFiles)
baseFileName = theFiles(k).name;
fullFileName = fullfile(theFiles(k).folder,baseFileName);
originalImage = imread(fullFileName);
ROI = roipoly(originalImage,x,y); %apply ROI
imshow(ROI);
[rows, columns, numberOfColorChannels] = size(originalImage);
mask = poly2mask(x, y, rows, columns);
maskedRgbImage = originalImage .* cast(mask, 'like', originalImage); %Masking outside ROI
GRAY = rgb2gray(maskedRgbImage); %Grey scaling the image
%Binarizing image using edge detection
BW = edge(GRAY,'canny',0.4);
[B,L] = bwboundaries(BW, 'noholes');
STATS = regionprops(L, 'all'); % we need 'BoundingBox' and 'Extent'
hold on
%Detecting shape
figure,
imshow(originalImage),
hold on
T = [];
filename3 = [sprintf('%01d',k) '.jpg'];
fullname3 = fullfile(currentFolder,'Object detected images',filename3);
for i = 1 : length(STATS)
W(i) = uint8(abs(STATS(i).BoundingBox(3)-STATS(i).BoundingBox(4)) < 0.1); %If width and height of bounding box are equal(circle,square), W(i)=1, otherwise W(i)=0
W(i) = W(i) + 2 * uint8((STATS(i).Extent - 1) == 0 ); % Extent =1; If circle/ellipse, back term=0, rec/sqr back term =2
W(i) = W(i) + 4 * uint8((STATS(i).Extent - 1) <= 0.7854); %Extent = pi/4 case ellipse/circle
centroid = STATS(i).Centroid;
switch W(i)
case 5 %circle
plot(centroid(1),centroid(2),'wO');
x_centroid = centroid(1:2:end);
y_centroid = centroid(2:2:end);
T = [T; x_centroid y_centroid];
ax = gca;
exportgraphics(ax,fullname3)
case 2 %rectangle
plot(centroid(1),centroid(2),'wX');
x_centroid = centroid(1:2:end);
y_centroid = centroid(2:2:end);
T = [T; x_centroid y_centroid];
ax = gca;
exportgraphics(ax,fullname3)
case 3 %square
plot(centroid(1),centroid(2),'wS');
x_centroid = centroid(1:2:end);
y_centroid = centroid(2:2:end);
T = [T; x_centroid y_centroid];
ax = gca;
exportgraphics(ax,fullname3)
case 4 %ellipse
plot(centroid(1),centroid(2),'w+');
x_centroid = centroid(1:2:end);
y_centroid = centroid(2:2:end);
T = [T; x_centroid y_centroid]
ax =gca;
exportgraphics(ax,fullname3)
end
end
close
end
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Respuestas (1)
Image Analyst
el 25 de Nov. de 2022
You can store all centroids right after you call regionprops, if you want
STATS = regionprops(L, 'all'); % we need 'BoundingBox' and 'Extent'
allCentroidsXY = vertcat(STATS.Centroid)
7 comentarios
Image Analyst
el 30 de Nov. de 2022
Those are JPG artifacts. That is why you should never use JPG images for image analysis if you can avoid it. So change your mask to
whiteMask = (r > 240) & (g > 240) & (b > 240);
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