How to fix Index position 3 exceeds array bounds (must not exceed 1)

I'm doing cropping and zero padding for bounding box images. However, there is error 'Index in position 3 exceeds array bounds (must not exceed 1).' I don't understand the error and location of 'index in position 3' . Hence, I can't solve it.

Please help me with this problem. Below are my codes.

%% Bounding box
imbwlabel=bwlabel(I8); %bwlabel works only in binary (b&w,double) image
figure;
imshow(label2rgb(imbwlabel)); %this is important bcs it helps to create the bounding box 
%in colored (uint8,unit16 etc) image and not in binary (b&w) image

bboxes=regionprops(imbwlabel,'BoundingBox');
[L, n]=bwlabel(I8);
bboxes=regionprops(I8,'BoundingBox','Centroid');

figure;imshow(I10);%title('Image with Bounding box'); 
axis image off
hold on
for k=1 : length(bboxes)
    CurrBB=bboxes(k).BoundingBox;
    %         cent=cat(1,bboxes.BoundingBox);
    %         plot(cent(:,1),cent(:,2),'g*')
    rectangle('Position', [CurrBB(1),CurrBB(2),CurrBB(3),CurrBB(4)], 'EdgeColor','m','LineWidth',2)
end
hold off


%% Crop image from bounding box
if ~isempty(bboxes)
    for p=1:length(bboxes)
        CurrBB=bboxes(p).BoundingBox;
        obj = imcrop(I8,CurrBB);
        [m, n, l]=size(obj);
        if (m > 227 || n > 227) 
            obj=imresize(obj,[227 227]);
        end
        I12=zeros(227,227);
        I12=uint8(I12);
        for i=1:m-1
            for j=1:n-1
                for k=1:3
                    I12(i,j,k)=obj(i,j,k);
                end
            end
        end
        figure;imshow(I12);
        %         figure;imshow(obj);
        imwrite(I12,sprintf('%dpad.png',p));
    end
end

Answer 1

[KSSV]

This error is simple.. you are trying to extract more number of elements then present. I suspect, you have a black and white image and you are trying to consider it as RGB and tried to extarct extra index.

% Demo
I = rand(10,10,3) ;  % 3D matrix 
R = I(:,:,1) ;  % no error 
G = I(:,:,2) ;  % no error 
B = I(:,:,3) ;  % no error 
%
I = rand(10) ; % 2D matrix 
I1 = I(:,:,1) ;  % no error 
I2 = I(:,:,2) ;  % error, there is no second matrix 

Index in position 3 exceeds array bounds. Index must not exceed 1.

In the same, way check the dimensions of the matrix, where you tried to extract like shown above.

[Erza Naziha]

Thanks for answering. Fyi, the resulted images from bounding box are in RGB. But I don't understand why still have error. Yet to find the solution.

[Erza Naziha]

hi again. Want to tell you that I've solved the problem already. Like you said, I'm expecting it to be RGB images but I accidently read the grayscale image. The error comes from this line

obj = imcrop(I8,CurrBB);

suppose to be I10 (RGB) instead I8(grayscale).

Thank so much for the hint!

[KSSV]

Perfect....

Happy Coding....Enjoy MATLAB. :)