How to compare two matrix?

redChannel = IM(:, :, 1);
greenChannel = IM(:, :, 2);
blueChannel = IM(:, :, 3);

for yourNumber = 1 : max(labelimg(:))
    thisLabel = labelimg == yourNumber; % for example 2 or 3 or whatever region you want.
    meanR(yourNumber) = mean(redChannel(thisLabel));
    meanG(yourNumber) = mean(greenChannel(thisLabel));
    meanB(yourNumber) = mean(blueChannel(thisLabel));
end

table(neigbor label)=
     2 3 4 5
  2  1 
  3  1 1 
  4  1 1 1
  5  1 0 1 1

I got a table which show the neighbor label and I got mean rgb for each label, I just need loop through the left triangle because another part is same.

The mean value for the label is double type, how I can round to integer only?

I got the mean of each label region and then I now want to compare them.

for i=2 : max(table(:))
for j=2:max(table(:)) 
   if(i,j+1)=1  %1 mean 2 label are neighbor
      if compare(j+1,i)<=(rgb+-5) %then reassign the label 
         if (i>j+1)  label i  = label j+1   %always assign to smaller label
             else  label j+1 = label to i

Final result I hope to get is like this

label 4 and 5 is within(rgb+-5) with label 2 so all assign to label 2

label =
   3 3 3 3 3 3            
   1 1 1 1 1 1            
   1 2 2 1 4 1             
   1 1 1 1 4 1            
   5 5 5 1 1 1             
   5 5 5 5 5 5  
result = 
     3 3 3 3 3 3            
     1 1 1 1 1 1          
     1 2 2 1 2 1            
     1 1 1 1 2 1            
     2 2 2 1 1 1             
     2 2 2 2 2 2

Answer 1

[Walter Roberson]

abs(meanR(j+1)-meanR(i)) <= 5 &&
abs(meanB(j+1)-meanB(i)) <= 5 &&
abs(meanG(j+1)-meanG(i)) <= 5

[Tan Wen Kun]

This solve the problem, did not need to using compare, I forget can do like this by using absolute.

for i=2 : max(table(:))
for j=2:max(table(:)) 
  if(i,j+1)=1  %1 mean 2 label are neighbor  
     if (abs(meanR(i,j+1)-meanR(i,j)) <= 5 &&
         abs(meanB(i,j+1)-meanB(i,j)) <= 5 &&
         abs(meanG(i,j+1)-meanG(i,j)) <= 5)

This statement true, I want to reassign label to smaller label. Below code is correct?

     if (label(i,j)>label(i,j+1))  
           label(i,j)  = label(i,j+1)   %always assign to smaller label
     else  label(i,j+1) = label(i,j)

[Walter Roberson]

The definition of meanR and so on that you show in your original post are indexed only by a single value, not by two values.

if(i,j+1)=1

is not valid syntax, not even if you change the = to == . You want

if table(i,j+1) == 1

You also do not want to use

for i=2 : max(table(:))

because table consists entirely of 0 and 1 so max() of it is going to be 1, and for i=2:1 is not going to do anything. You want to run i to the maximum label, not the maximum table.

[Tan Wen Kun]

ya,it is one value for meanR, ytd I think and write wrongly

so I should use for i=2:max(label(:)) ?

label =

1 1 1 1 1
1 2 1 3 1
1 1 1 1 1

I want to made label 3 to label 2, how to do?

for i=2 : max(label(:))
    for j=2:max(label(:)) 
       if table(i,j+1)==1  %1 mean 2 label are neighbor  
         if (abs(meanR(j+1)-meanR(i)) <= 5 && abs(meanB(j+1)-meanB(i)) <= 5 && abs(meanG(j+1)-meanG(i)) <= 5)
                 if label(j+1)>i
                     label(j+1)=label(i);
                 else
                     label(i)=label(j+1);
                 end

Error in (line 122)

          if (abs(meanR(j+1)-meanR(i)) <= 5 &&
         abs(meanB(j+1)-meanB(i)) <= 5 && abs(meanG(j+1)-meanG(i))
         <= 5)

why i got this problem?

[Walter Roberson]

maxlab = max(label(:));
for i = 1 : maxlab
  for j = 1 : maxlab - 1
  if table(i,j+1) == 1
    if abs(meanR(j+1)-meanR(i)) <= 5 &&
       abs(meanB(j+1)-meanB(i)) <= 5 && abs(meanG(j+1)-meanG(i))
       <= 5
      if label(i, j+1) > label(i, j)
        label(i, j+1) = label(i,j)
      else
        label(i,j) = label(i, j+1);
      end
    end
  end
end

Answer 2

[Image Analyst]

The answer to "how I can round to integer only?" is to use the int32() function.

[Tan Wen Kun]

how to compare mean value for both label? what is the function name?

[Jan]

@Tan Wen Kun: The function name of what? What should the command "compare(j+1,i)<=(rgb+-5)" do? It is impossible to guess, what you want.

[Tan Wen Kun]

I want to compare the mean value of label which is neighbor.

I want to compare whether the meanR, meanG, meanB value of label 2 and label 3 is within 5 or not? If this 3 statement true then I reassign label 3 to label 2.

[Image Analyst]

I have no idea what that triangular table is so I can't answer. And I don't know what reassigning labels is going to do. I think you're trying to do some kind of region growing/merging because you started out with a bad segmentation that was made worse by oversegmentation by watershed and now you're trying to fix it in a way that won't work.

[Tan Wen Kun]

table(neigbor label)=
     2 3 4 5
  2  1 1 1 1
  3  1 1 1 0
  4  1 1 1 1
  5  1 0 1 1

this table is show which label is neighbor label.

What I mean triangular is because table(2,3) is same as table(3,2) so I do not need to check twice whether their rgb value is within 5 or not.

I only need check half side only