Integers can only be combined with integers of the same class, or scalar doubles.

red=I(:,:,1);
green=I(:,:,2);
blue=I(:,:,3);
R=(0.7*GRmean+(1-0.7)*LRmean);
G=(0.7*GGmean+(1-0.7)*LGmean);
B=(0.7*GBmean+(1-0.7)*LBmean);
    
r=red./R;          %ERROR
g=green./G;
b=blue./B;

[KALYAN ACHARJYA]

GRmeanr, LRmean...???

Have you defined??

[Sajina Rose]

Yeah.....I defined formula for that in my code.......It's nothing but just global and local mean of RGB....

[Ted Shultz]

What are your variable types? (command "whos") will tell you.

What error are you getting?

Answer 1

[John D'Errico]

READ THE ERROR MESSAGE!

R = uint8(1:5);
>> R./double(R)
Error using  ./ 
Integers can only be combined with integers of the same class, or scalar doubles. 

Is double( R ) a scalar double? In fact, it is not. It is a vector of doubles.

So MATLAB will not allow you to perform that operation. The information was completely contained in the error message, if you think about what it says and what you just did.

Can you fix it? Well, yes, that is trivial. In the line:

r=red./R;  

Change it to read

r=double(red)./R;  

red is a vector of INTEGERS. R is a vector of doubles. So to do that operation, you need to convert the vector red into a vector of doubles.

[Guillaume]

Another option would be to convert the original image to double with im2double:

I = im2double(I);
%rest of the code as it was

matlab expects images of type double to have intensities in the range 0-1, so im2double may be better than straight double conversion.

But yes, the error message explained what the problem is.