How to remove non-barcode region in an image? - MATLAB

Well, i have already explained it in your previous question How to find the location of red region in an image using MATLAB? , but with a opencv code and output images.

Instead of asking for code, try to implement it yourself.

Below is what to do next.

1) convert image 'C' in your code to binary.

2) Apply some erosion to remove small noises.( this time, barcode region also shrinks)

3) Apply dilation to compensate previous erosion.(most of noise will have removed in previous erosion. So they won't come back)

4) Find contours in the image.

5) Find their area. Most probably, contour which has maximum area will be the barcode, because other things like letters, words etc will be small ( you can understand it in the grayscale image you have provided)

6) Select contour with max. area. Draw a bounding rectangle for it.

Its result is already provided in your previous question. It works very nice. Try to implement it yourself with help of MATLAB documentation. Come here only when you get an error which you don't understand.

 %%hi, i am ading my code to yours at the end of your code%%%% clear all; rgb = imread('barcode.jpeg'); % Resize Image rgb = imresize(rgb,0.33); figure(),imshow(rgb); % Convert from RGB to Gray Igray = double(rgb2gray(rgb)); Igrayc = Igray; % Calculate the Gradients [dIx, dIy] = gradient(Igray); B = abs(dIx) - abs(dIy); % Low-Pass Filtering H = fspecial('gaussian', 10, 5); C = imfilter(B, H); C = imclearborder(C); imshow(Igray,[]); figure(),imagesc(C);colorbar; %%%%%%%%%%%%%%%%%%%%%%%%from here my code starts%%%%%%%%%%%%%%%% bw = im2bw(C);%%%binarising the image % imshow(bw); %%%%if there are letters or any other noise is present around the barcode %%Note: the size of the noise and letters should be smaller than the %%barcode size labelImage = bwlabel(bw,8); len=0;labe=0; for i=1:max(max(labelImage)) a = find(labelImage==i); if(len<length(a)) len=length(a); labe=i; end end imag = zeros(size(l)); imag(find(labelImage==labe))=255; % imtool(imag); %%%if Necessary do errossion % se2 = strel('line',10,0); % imag= imerode(imag,se2); % imag= imerode(imag,se2); [r c]= find(imag==255); minr = min(r); maxc = max(c); minc = min(c); maxr = max(r); imag1 = zeros(size(l)); for i=minr:maxr for j=minc:maxc imag1(i,j)=255; end end % figure,imtool(imag1); varit = find(imag1==0); Igrayc(varit)=0; %%%%%result image having only barcode imshow(Igrayc,[]); %%%%%original image figure(),imshow(Igray,[]); 

Hope it is useful