Index in position 1 is invalid. Array indices must be positive integers or logical values

Hi everyone,

I am not sure why I am getting this error since I feel like my indices are all positive integers, however, I am still getting this error😅 hanks so much in advance.

Here is my code:

The error is showing for the line

 cover(currentRow,currentColumn)= payload(K); % this is the line that throws the error

% create and embed message - - - - - - - - - - - - - - - - - 

coverorig = imread('turtle.png');
% infooriginal = imfinfo('turtle.png'); % gets information about this file

cover1 = imresize(coverorig, [1024 1024]);
cover = rgb2gray(cover1);
[M,N] = size(cover); %rows and cols in cover

imwrite(cover1, 'turtle.png');
imwrite(cover, 'grayscale_turtle.png');

capacity = ceil(log2(M*N));  % max length of payload can embed, 2^capacity
rate = 0.1;

K = round(rate*(M*N - capacity)); % length of payload to create and embed
payload = round(rand(1,K)); % create random vector of 0s and 1s of correct length

currentColumn = N;
currentRow = M;
currentPayloadIndex = K;


for currentRow = 1:1:1e6
    for currentColumn = 1:1:1e6
        cover(currentRow,currentColumn)= payload(K);
        K = K - 1;
        currentColumn = currentColumn - 1;
            if K == 1
                fprintf('message fully embedded')
            end
if K == 1
    fprintf('message fully embedded')
end 
    currentColumn = N;
    currentRow = currentRow - 1;
    end
end

[julia zhang]

I wanted to add that I am trying to write an m file that creates ands embeds a message into an image.

Answer 1

[Sulaymon Eshkabilov]

There are a couple of inconsistencies that cause this problem in the code:

%
 currentColumn = currentColumn - 1; % Return to be "0" in the next iteration
 currentRow = currentRow - 1;       % The same
% These declared variables above are never used in the loop:
currentColumn = N;
currentRow = M;