Array indices must be positive integers or logical values (image processing)

Question

Yohanes Setiawan 2019-3-22

评论： Yohanes Setiawan 2019-3-22

x = imread('cameraman.jpg');
[M,N]=size(x)
for i=1:M
    for j=1:N
        I=x(i,j);
        x(i,j)=xL(I)+( L(I)*lambda(i,j) );   
    end
end

where

xL is 1x256 dimension, xL is 1x256 dimension, and lambda is 256x256 dimension which is same with x that has 256x256 dimension.

I get this error:

Array indices must be positive integers or logical values.
Error in edge_enhancing (line 134)
            x(i,j)=xL(I)+( L(I)*lambda(i,j) );

Ple

Answer 1

KSSV 2019-3-22

I=x(i,j);   % here I will be pixel value of image, it cannot be a index
x(i,j)=xL(I)+( L(I)*lambda(i,j) );   

Note that in MATLAB indices should be positive integers or logicals.

A = rand(10) ; 
A(1)  % no error 
A(10)  % no error 
A(5,4)  % no error 
A(-1)   % error 
A(0)    % error 
A(23.5)   % error

KSSV 2019-3-22

编辑：KSSV 2019-3-22

Try using double/logical. If the vlaue is 250, it should work. Read about double. But I am surprised..why you want to index with a pixel value.

using double will output the same thing. I want to index with a pixel value because I want to multiply lambda with the L in k-intensity.