Removing white background from Barcode image(s)

Question

adam campbell 2020-11-19

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/653943-removing-white-background-from-barcode-image-s

评论： adam campbell 2020-11-20

采纳的回答： Rik

Hello,

I'm currently trying to process a large number of barcodes.

I'm using a function available on the forums called generateBarcodeCode39().

it outputs the generated barcode image(s) and saves each respective figure to jpg in a directory.

My Problem:

The size of my barcodes are different. Some times I will have a string of text that is 4-5 characters long, others more.

this results in different image sizes of barcodes that are saved.

i'm trying to have one size inputted into a formatted excel document, which is why the size of the barcodes are important.

Question:

How would I go about removing just the white background that is generated when creating a matlab figure for each image? I've tried imcrop, and it does work for some cases, but it's not a one size fits all solution.

should i just create different inputs to the imcrop() function that specifies each barcode case and crop it accordingly?

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adam campbell 2020-11-19

编辑：adam campbell 2020-11-19

在 MATLAB Online 中打开

yes. let me attach. I'm actually calling the function in a loop, displaying in a figure, and then saving it off in a jpg.

function link: https://www.mathworks.com/matlabcentral/fileexchange/56010-barcode-39-generator-matlab

A section of my code, that takes in a cell array of numbers i want turned into barcodes, creates figure, and saves as image:

for i = 1:length(CellData)
% Generate a logical array containing the barcode
barcodeArray = generateBarcodeCode39(num2str(CellData{i,3}), barWidth, barHeight, appendTerminationMarkers);
% Generate an image of the barcode
figure(i)
fh = imshow(~barcodeArray);  % Have to NOT the array, other wise MATLAB displays 1 as black and 0 as white
%not neccessary 
if strcmp(class(CellData{i,3}),'char') == 1
saveas(figure(i),[pwd strcat('/Barcodes/',(CellData{i,3})) '.jpg']) ; 
else 
saveas(figure(i),[pwd strcat('/Barcodes/',num2str(CellData{i,3})) '.jpg']) ; 
end
end 

adam campbell 2020-11-19

在 MATLAB Online 中打开

this section of code is something i came up with to crop the images, and then save over the existing from the directory. however since they seem to be different size from the function, my current "cropar" variable that acts as RECT in the imcrop() help doesn't work for all cases. see below:

cropar = [130 50 525 190] ;
for i = 1:length(bcdir)
    
I = imread(bcdir{i,1});
I2 = imcrop(I,cropar);
figure(i)
imshow(I2)
if strcmp(class(bcdir{i,1}),'char') == 1
saveas(figure(i),[pwd strcat('/Barcodes/',(bcdir{i,1})) ]) ; 
else 
saveas(figure(i),[pwd strcat('/Barcodes/',num2str(bcdir{i,1})) ]) ; 
end
end

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Answer 1

Rik 2020-11-20

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/653943-removing-white-background-from-barcode-image-s#answer_550768

在 MATLAB Online 中打开

The easiest solution is to not add the border in the first place:

barWidth = 3;barHeight = 100;appendTerminationMarkers = false;i=1;CellData{i,3}=123456;
barcodeArray = generateBarcodeCode39('123456', barWidth, barHeight, appendTerminationMarkers);
if isa(CellData{i,3},'char')
    imwrite(barcodeArray,fullfile(pwd,'Barcodes',[        CellData{i,3}  '.jpg']));
else
    imwrite(barcodeArray,fullfile(pwd,'Barcodes',[num2str(CellData{i,3}) '.jpg']));
end