How to generate QR code of image in MATLAB R2019b.

I want to generate QR code of document image in MATLAB.

Please help

Thanks in advance

[Jan]

QR codes are images. Usually they are created to encode a text. So it is not clear, what you want to achieve.

[Balkar Singh]

I want to use a image as a QR code. For example how can I generate a QR code of the uploaded image

[Walter Roberson]

The largest QR code is too small to hold that image. However it might be the case that it could fit a compressed version of the image.

[Balkar Singh]

Ok Sir, but how to generate it. Please help

Answer 1

[Walter Roberson]

filename = 'Tu_logo.png';

[fid, msg] = fopen(filename, 'r');
if fid < 0
    error('could not open file "%s" because "%s"', msg)
end
bytes = fread(fid, 'uint8=>char', [1 inf]);
fclose(fid);

qr_array = encode_qr(bytes, [160 160]);

https://www.mathworks.com/matlabcentral/fileexchange/29239-qr-code-encode-and-decode

[Balkar Singh]

Thanks

[Balkar Singh]

@Walter Roberson During the execution of qr code i got the following error

The import statement 'import com.google.zxing.qrcode.QRCodeWriter.' cannot be found or cannot be imported. Imported names must end with '.*' or be fully qualified.

Error in embd (line 13)

qr_array = encode_qr(bytes, [160 160]);

[Walter Roberson]

Documentation says "A wrapper to the zxing library ( http://code.google.com/p/zxing/ )." so I would imagine that you need to load that in and add it to your javapath

[Walter Roberson]

Note that the code above replies on the File Exchange contribution that I linked to. If you are using the newer https://www.mathworks.com/matlabcentral/fileexchange/41437-qr-code-encoder then instead of passing [160 160] you would pass 'Size', [160 160]

[Andrew]

Unfortunately, this solution requires compiling and installing a java library, and the image processing toolbox. Heavy dependencies for this task.

[Walter Roberson]

@Andrew

It does not appear to me to require the Image Processing Toolbox. Did I overlook something?

It is not clear to me how requiring several hundred lines of MATLAB source code is less "heavy" then installing a well-tested Java library ? And if it were written in MATLAB, it is pretty likely it would rely on routines from the Image Processing Toolbox.

[Andrew]

@Walter Roberson Over on the right side of the official Matlab page there's a 'Requires' line:

____________________________________________

Requires

• Image Processing Toolbox

Download and build the core and javase components of the zxing library (see description) and make sure they are in Matlab's dynamic java classpath.

____________________________________________

There's another QR code generation script here which does NOT require the image processing toolbox, and it attempts to download and 'install' the needed pre-built java code on its own. Personally, I found this much easier to work with, because it demonstrates how to handle its own java dependency, which greatly lightens the work of using the library for the first time, compared to asking a user to build a java library, which requires putting together another toolchain.

[Image Analyst]

@Andrew this is what I see (snapshot of File Exchange entry)

And I'm not sure who's code it is. It was posted by ejs but the function says the author is Lior Shapira (at the beginning) and [e-mail] at the end. Did they just post someone else's code as their own?

[Andrew]

@Image Analyst That's a good link. The previous link that was accepted in this thread, and says it requires image acquisition toolbox:

https://www.mathworks.com/matlabcentral/fileexchange/29239-qr-code-encode-and-decode

However neither link automatically addresses how to obtain and 'install' and use the java dependency, like this link does:

https://www.mathworks.com/matlabcentral/fileexchange/61612-qr-code-as-image?s_tid=srchtitle

My point is that a guideline for posting scripts is needed. Script authors who publish scripts with dependencies should think about how to minimize the dependencies listed, lighten the workload of using those dependencies as much as possible for users who aren't familiar with them, and if possible make obtaining and using them seamless. The last link in this post appears to have done that, and included example files for an out-of-the-box demo run.

Cheers!

[Walter Roberson]

The one that mentions Image Processing Toolbox was posted in the 2010 timeframe. It does not actually use any functions from the Image Processing Toolbox. The demonstration function does call imagesc(), but that has always been part of basic MATLAB. There might have been some confusion because in early enough versions of MATLAB, imshow() was part of the Image Processing Toolbox.

[ejs]

Hi folks, the Guilty is here,

The updated code, https://se.mathworks.com/matlabcentral/fileexchange/41437-qr-code-encoder is based on the https://se.mathworks.com/matlabcentral/fileexchange/29239-qr-code-encode-and-decode with these differencies (if I recall correctly): UTF-8 as default character set; possibility to specify size of the message, as we needed the fixed dimensions of the QR code; possibility to alter error correction. It's all in the header.

An no, to my understanting it does not use neither Image Processing toolbox, nor has somenting in common with 3D scene control. Not sure how the categories are assigned in the Fileexchange.

I can't recall the exact procedure of specifyining the ZXing libraries. As ZXing written Java, the same as Matlab, there was some simple procedure to add then to the path. If anyone is still interested in it, I can try to restore the procedure.

Again, it was 12 years ago, there was no online QR services at that time.

[Balkar Singh]

Thank you