how to fix Attempt to grow array along ambiguous dimension-Error?

I am trying to draw rectangle around the region where there are only the characters and numbers.But I'm getting error.I have attached the code and the error.please help mein rectifying it.

Error is:

Attempt to grow array along ambiguous dimension.

Error in tes (line 33)

redChan(perim) = 255;

% Clear all varibles and close all windows
clear all;
close all;

% Read in image
imorig = imread('test3.png');

% Threshold and invert
im = ~im2bw(imorig);

% Find bounding boxes of all characters
s = regionprops(im, 'BoundingBox');
bbox = round(reshape([s.BoundingBox], 4, []).');

% Create a blank image and for each box, fill in with white
outImg = false(size(im));
for idx = 1 : size(bbox,1)
    outImg(bbox(idx,2):bbox(idx,2)+bbox(idx,4), ...
        bbox(idx,1):bbox(idx,1)+bbox(idx,3)) = true;
end

% Close with a very large structuring element
se = strel('square', 20);
outImg2 = imclose(outImg, se);

% Find the perimeter of this object, then take the original image and
% the pixels that belong to this boundary.  Colour all of these pixels red
% for illustration
redChan = imorig(:,:,1);
greenChan = imorig(:,:,2);
blueChan = imorig(:,:,3);
perim = bwperim(outImg2,8);
redChan(perim) = 255;
greenChan(perim) = 0;
blueChan(perim) = 0;
out = cat(3,redChan,greenChan,blueChan);

figure;
subplot(1,2,1);
imshow(imorig);
title('Original image');
subplot(1,2,2);
imshow(out);
title('Image with perimeter overlaid');

Answer 1

[KSSV]

Check the sizes of perim and redChan . They are

 perim        220x684            150480  logical              
 redChan      219x683            149577  uint8  

When you use :

 redChan(perim) = 255;

YOu are trying to extract more number of dimensions, then existing. So the error. YOu need to do proper intiailizations.

[ezhil K]

OK.So what should I specify there?

[KSSV]

Use imcrop and get the both images to the same dimension.....