ZXing library can't decode Datamatrix barcode

Question

I'm trying to use ZXing library to decode Datamatrix barcode. Here are my code sample:

BufferedImage bi = img.getBufferedImage();

Hashtable<DecodeHintType, Object> hints = new Hashtable<DecodeHintType, Object>();
hints.put(DecodeHintType.TRY_HARDER, Boolean.TRUE);

LuminanceSource source = new BufferedImageLuminanceSource(bi);
BinaryBitmap bitmap = new BinaryBitmap(new HybridBinarizer(source));
DataMatrixReader dataMatrixReader = new DataMatrixReader();

try {
    Result res = dataMatrixReader.decode(bitmap,hints);
    System.out.println("resultText = "+res.getText());
} catch (Exception e) {
    System.out.println("failed to get resultText");
    e.printStackTrace();
}

I've seen almost the same samples many times accross https://stackoverflow.com/ and other sites, but this approach does not working for me in this form.

As a source I'm using images grabbed from IR-camera. Here are example image: As you see, the barcode is almost exactly at the center of an image, as Sean Owen recommended here and here. If I programmatically convert this image to black&white and crop image to bound barcode with some white space around it only, then ZXing works perfectly with images like this. But the problem is that barcode in real could have little deformations, so my simple algorythm can't help me to crop image properly. More over barcode could be placed not exactly in the center of an image and cold have a little bit different brightness. I saw threads mentioning OpenCV capabilities to find out placement of speciects objects on the image, like this one, but they are quite old. Is something changed since then? And what should i yet certainly consider to write 100% reliable datamatrix decoder (and detector) in my specific situation?

I decided to supply LuminanceSource and BinaryBitmap images made of .toString() text output of correcponding objects for reference: http://s28.postimg.org/l53sykhx9/Binary_Bitmap.png

and /65z0vlbpl/Luminance_Source.png (at the same domain). They are looking good and ready for decoding, but what is wrong with decoding then.

After all this image and similar ones recognized and decoded very well with smartphone software and i'm just wanted achieve same results.

Answer 1

you need to enable it from settings programmatically or manually.

in class DecodeThread.java you can see the line that enables data matrix encoding

decodeFormats.addAll(DecodeFormatManager.DATA_MATRIX_FORMATS);