circle centered on the object

I have a reference image that contains 10 items. I have separate objects in small images (cut from the reference image). Code sequence must find an object that you selected (if the write code sequence "object 1" must make a circle around the "object 1" If it says "Objective 2" to make the circle around the "item 2" Can you help me please? reference image

http://www.uploadup.com/di-5Y01.jpg

Object

http://www.uploadup.com/di-FNMJ.jpg

clear; clc;
I = imread('di-5Y01.jpg');
object = imread('di-FNMJ.jpg');
c = normxcorr2(object(:,:,1),I(:,:,1));
[max_c, imax] = max(abs(c(:)));
[ypeak, xpeak] = ind2sub(size(c),imax(1));
corr_offset = [(xpeak-size(object,2)) (ypeak-size(object,1))];
figure, imshow(I); hold on;
rectangle('position',[corr_offset(1) corr_offset(2) 30 60],...
        'curvature',[1,1],'edgecolor','g','linewidth',2);

Code sequence works but not centered the circle on the object.

Answer 1

[Chandra Kurniawan]

Hello, Why don't you use rectangle??

Why must circle??

I have my code detect the exact area if you consider to use rectangle??

Would you use rectangle? Then I'll give u the code

Here the results :

Object 1:

Object 2:

Object 3:

Answer 2

[Chandra Kurniawan]

Here the code if you consider to use rectangle

I = imread('di-5Y01.jpg');
object = imread('obiect1.jpg');
[m n o] = size(object);

c = normxcorr2(object(:,:,1),I(:,:,1));
[max_c, imax] = max(abs(c(:)));
[ypeak, xpeak] = ind2sub(size(c),imax(1));
corr_offset = [(xpeak-size(object,2)) (ypeak-size(object,1))];

figure, imshow(I); hold on;
rectangle('position',[corr_offset(1) corr_offset(2) n m],...
          'edgecolor','g','linewidth',2)

I hope this helps you :)

[Tomescu]

Thank you very much!

Answer 3

[Chandra Kurniawan]

Hello, It's quite simple.

You just need to increase or decrease the 'corr_offset' values with small random value.

I = imread('di-5Y01.jpg');
object = imread('di-FNMJ.jpg');

c = normxcorr2(object(:,:,1),I(:,:,1));
[max_c, imax] = max(abs(c(:)));
[ypeak, xpeak] = ind2sub(size(c),imax(1));
corr_offset = [(xpeak-size(object,2)) (ypeak-size(object,1))];

figure, imshow(I); hold on;
rectangle('position',[corr_offset(1)-9 corr_offset(2)+5 45 45],...
          'curvature',[1,1],'edgecolor','g','linewidth',2);

The result :

[Tomescu]

Go on that obiect1 but when I select another object( obiect5 or obiect10)the circle is not centered on that object.

Can you help me?

http://imageshack.us/photo/my-images/690/obiect5.jpg/

http://imageshack.us/photo/my-images/651/obiect10.jpg/

[Chandra Kurniawan]

Hello, Why don't you use rectangle??

Why must circle??

I have my code detect the exact area if you consider to use rectangle??

Would you use rectangle? Then I'll give u the code

[Tomescu]

Hello!

I found this code on another forum.

The problem is that I think it's a bit complet.Can you look over it please?

Thank you.

%#read & convert the image

imgCol = imread('http://i.stack.imgur.com/tbnV9.jpg');

imgGray = rgb2gray(img);

obj = rgb2gray(imread('http://i.stack.imgur.com/GkYii.jpg'));

%# cross-correlate and find the offset

corr = normxcorr2(...);

[~,indx] = max(abs(corr(:))); %# Modify for multiple instances (generalize)

[yPeak, xPeak] = ind2sub(...);

corrOffset = [yPeak - ..., xPeak - ...];

%# create a mask

mask = zeros(size(...));

mask(...) = 1;

mask = imdilate(mask,ones(size(...)));

%# plot the above result

h1 = imshow(imgGray);

set(h1,'AlphaData',0.4)

hold on

h2 = imshow(imgCol);

set(h2,'AlphaData',mask)

Answer 4

[Tomescu]

The ptoject say that the object must be identify in a circle, but i hope that it whont be a problem if is in a rectangle.

[Chandra Kurniawan]

So, how about your own decision?

You'll stay use circle with non exact area or

You'll use rectangle with exact area.

You can ask your professor about it :)