find spots in image

27 visualizaciones (últimos 30 días)
PJM
PJM el 27 de Jul. de 2013
Comentada: Image Analyst el 30 de Mzo. de 2014
and I use the code, then I can find the spots.
----------
clear all;
Cimg=imread('CropTest1.jpg','jpg');
Gimg=rgb2gray(Cimg);
BW=Gimg>150;
rp=regionprops(BW,Gimg,'WeightedCentroid');
disp('Centroiding is done.');
figure(1); image(Cimg); axis image; hold on;
n=numel(rp);
for i=1:n
plot(rp(i).WeightedCentroid(1), rp(i).WeightedCentroid(2), 'r*')
end
----------
and I have coordinates of all spots.
then I want to do these
- express Center spot -> (0,0)
- find missing spots (-1,3),(5,1),(1,-5) and output the message: '(-1,3),(5,1),(1,-5) are missing!'
- delete one spot in double spots that use this idea: distance of two spots(well, I seem to be able to do this.)
thank you for your advice and help.

Respuesta aceptada

Image Analyst
Image Analyst el 27 de Jul. de 2013
I can't see your images, though I'm in Beijing this week and imageshack.us seems to be another domain in a long list of web sites I've encountered that are banned by the government of China. Nonetheless, I'll try to help as best I can without seeing your images. I'm assuming that you have a 10 by 10 array of possible locations of the circles. You first define a logical array initialized to false that says whether or not you have a circle there. Then set it to true when you find a circle there. Try something like this (untested)
circlePresent = false(10,10);
% Then loop over circles you have found setting the array to true.
centroids = [rp.WeightedCentroid];
[rows, columns] = size(BW);
for k = 1 : length(rp)
if centroids(k, 2) < rows/10
row = 1;
elseif centroid(k, 2) < 2*rows/10
row = 2;
elseif centroid(k, 2) < 3*rows/10
row = 3;
% and so on up to 10.
% Then do the same for columns.
if centroids(k, 1) < columns/10
column = 1;
% etc.
% Now set the array to true for this circle
circlePresent(row, column) = true;
end
% Now find missing elements
[missingRows, missingColumns] = find(~circlePresent);
% Print out all the missing circles array locations.
for k = 1 : length(missingRows)
fprintf('There is a circle missing at row %d, column %d.\n', ...
missingRows(k), missingColumns(k));
end
  5 comentarios
ajinkya nikam
ajinkya nikam el 30 de Mzo. de 2014
i did not get anything. matlab only tells that CONTINUE ENTERING STATEMENT what should do
Image Analyst
Image Analyst el 30 de Mzo. de 2014
I have no idea what you're referring to. Start your own thread, post your own code and image, and I'll see what I can do.

Iniciar sesión para comentar.

Más respuestas (1)

Elad
Elad el 27 de Jul. de 2013
I would try imfindcircles(), (or hough transform to find circles if you don't have the toolbox). You can adjust the sensitivity and edge until you find all the spots. Than you can calculate the average intesity in each circle and have full control on your results.
Here is an example in the image processing blog, using imfindcircles: http://imageprocessingblog.com/detecting-and-counting-objects-with-circular-features/
  4 comentarios
Elad
Elad el 27 de Jul. de 2013
Editada: Elad el 27 de Jul. de 2013
[centers, radii] = imfindcircles(clb1,[8 15],'Sensitivity',0.91,'Edge',0.01);
gets all the spots but one.
[centers, radii] = imfindcircles(clb1,[8 15],'Sensitivity',0.9,'Edge',0.01,'ObjectPolarity','dark');
gets the last spot.
PJM
PJM el 27 de Jul. de 2013
Wow! actually, I feel the limit of regionprops when bright backgrounds. I will try this way.
Thank you for your help. :D

Iniciar sesión para comentar.

Categorías

Más información sobre Image Processing Toolbox en Help Center y File Exchange.

Etiquetas

Community Treasure Hunt

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

Start Hunting!

Translated by