Re-label a matrix after using bwlabel.

Partners I have a question. I'm working on the division of a matrix by means connected regions using labels through bwlabel, but it turns out a high number of connected regions. I have tried to simplify calculating the area of the labels and if areas are lower than the a value they are eliminated.

 [L, NUM] = bwlabel (M);
 regionrops s = (L, 'Area');
 y = [s.Area];
 ind = find (y <10)

 for j = 1:1959
 for i = 1:199
 for k = 1: length (ind)
 if (L (i, j) == 0 | | L (i, j) == ind (k))
 L (i, j) = 0
 end
 end
 end

 But when I delete the labels that meet the above condition. The matrix L is disordered. How can I order it?

 if the pixels that do not meet the condition I put to one and next step I apply bwlabel, only a label has been removed. Is there any function that reorders labels in the matrix L?

 Thanks and best regards

Answer 1

[Image Analyst]

Yes, it's called intlut(). But why do you want to reorder the labels? Anyway, back to your first question, there are other ways of getting rid of blobs less than 10 pixels in size including bwareaopen() and ismember(). See my BlobsDemo in the File Exchange : http://www.mathworks.com/matlabcentral/fileexchange/?term=authorid%3A31862

[Cristina]

Thank you very much for your answers. But I have a problem with intlut . What second matriz (?) do I put in input? B=intlut(L,?)

My problem is that I have the matrix L I want to modify to L2

L= 1 1 0 0 y yo quiero que reorder in L2= 1 1 0 0

0 0 5 5 0 0 2 2

7 7 0 0 3 3 0 0

7 0 9 9 3 0 4 4

I want to do this because I have that extract features the different region that composed an image using regionprops. With bwlabel I have a lot of regions (more than 1000) and I have to simplify it to 20 features. This algorithm is to select exudates in fondus eyes images

[Cristina]

Pardon

L= [1 1 0 0;0 0 5 5; 7 7 00; 7 0 9 9]

and I want

L2= [1 1 0 0; 0 0 2 2; 3 3 0 0;4 0 5 5]