Image Processing - How to separate barcode from the background

I'm wondering how to separate the barcode from background itself, and I have tried some different to remove the unwanted object but cannot remove fully , anybody has an idea!

http://www.mediafire.com/?n3q24a2acfjinui

%Read Image
RGB  = imread('barcode.jpg');
%Resize Image
RGB = imresize(RGB, 0.33);
%Convert from RGB to Gray
Gray = rgb2gray(RGB);
%Threshold Image to black and white
Threshold = graythresh(Gray);
BW = im2bw(Gray, Threshold);
%Remove Noise
BW2 = bwareaopen(BW,25000);
imshow(BW2)

Answer 1

[Chandra Kurniawan]

Hello, Kim

Here I have the code to do segmentation on your barcode image.

I hope this helps

rgb  = imread('barcode.jpg');
rgb = imresize(rgb,0.33);
Igray= rgb2gray(rgb);
Ibw = im2bw(Igray, graythresh(Igray));

Iarea = bwareaopen(Ibw,25000);
Iarea = imfill(Iarea,'holes');
stat = regionprops(Iarea,'boundingbox');
for cnt = 1 : length(stat)  
    area(cnt) = stat(cnt).BoundingBox(3) * stat(cnt).BoundingBox(4);   
end
[C I] = min(area);
Icropped = imcrop(Ibw,stat(I).BoundingBox);
imshow(Icropped);

Original Image :

Cropped Image :

[Kim]

Just nice!! This is what I need!! Thanks! :)

[Malta]

Why is there an error like this? Error using area (line 42) Must supply Y data or X and Y data as first argument(s).

Answer 2

[noosa]

I am trying to run this code but I get this error :

??? Error using ==> area at 44 Must supply Y data or X and Y data as first argument(s).

Can you help me please???

[Chandra Kurniawan]

Please post your code.

[noosa]

I am trying to run your code and I get that error linked to area command. How can I solve it please?

Thank you Chandra for your quick response !

[Chandra Kurniawan]

Hi, your error message said 'Error using ==> area at 44 Must supply Y data or X and Y data as first argument(s).'

It seem you have named your m-file with 'area.m', right?

However in your script 'area' was a variable.

Please try to rename your script with other name.

[noosa]

No I haven't name my file 'area.m', I named it 'barcode'

I got this error message because area is already a default command in matlab, so I renamed it 'v', I got this error:

??? Undefined function or variable 'v'.

Error in ==> barcode at 16

[C I] = min(v);

Then I have thought to check length(stat), I am surprised that it return 0 !

So the loop

for cnt = 1 : length(stat)

v(cnt) = stat(cnt).BoundingBox(3) * stat(cnt).BoundingBox(4);

end

will not work.

Do you know why length(stat) returns 0 ??

[Chandra Kurniawan]

Yes, I see the problem.

before line 'stat = regionprops(Iarea,'boundingbox');'

you should do area opening by 'Iarea = bwareaopen(Ibw,25000);', right?

It seem bwareaopen remove all object in your picture.

In other word, all objects in your image have area less than 25000.

That's the reason why length(stat) returns 0.

[noosa]

oh I see ! so how to fix the parameter 25000? is there any automatic method?

[Chandra Kurniawan]

Yes, just decrease the value.

Eq 24000 or less.

[noosa]

But I need to do this with many images, so I can't change the value each time :((( that's why I asked for automated method to determine this threshold !

[Chandra Kurniawan]

Just find the largest area and then use that value as threshold

Eq:

I = imread('cameraman.tif');

I = im2bw(I);

stat = regionprops(I,'area');

C(1:length(stat)) = stat(1:end).Area;

m = max(C);

J = bwareaopen(I,m);

imshow(J);

[noosa]

thank you ! I will try it :))

Answer 3

[mostafa alhamdany]

hi this code is not working and the error is : Error using area (line 35) Must supply Y data or X and Y data as first argument(s).

Error in barcode (line 15) [C I] = min(area); can anyone help me to solve it , please