Find location of cross in image.

Question

Hans Dohse 2019-12-23

回答： Rajani Mishra 2020-1-8

I have an image that contains a cross in it. It also also has circles, squares and other features.

How can I detect the location of the cross to sub pixel accuracy?

Matrox MIL has a Geometric Model Finder which works very well. Does Matlab have anything similar?

KALYAN ACHARJYA 2019-12-27

Can you share a sample image?

Answer 1

Rajani Mishra 2020-1-8

I have tried below code on an image containing a cross in it, it detects the center location of the cross.

Please refer below for the code:

img = imread('test.jpg');
I = rgb2gray(img);
BW = imbinarize(I,0.25);

2. As the result may have missing parts dilate the image to join the parts

se = strel('line',11,90);
BW2 = imdilate(BW,se);

3. Use morphological ‘shrink’ operation to shrink image to a point

BW3 = bwmorph(BW2,'shrink',Inf);

4. Find the position of the point

[row,col] = find(BW3);

Hope this helps.