Please help: QR Code Reading Problem.

[Steven Ang]

I am trying to create a code which can read the QR Code from an image file.
I found out that the code can work with PNG formatted file but cannot work with JPEG.

Can any one here help me to find out the reason why it doesn't work with JPEG?

public static void deCodeQRCode(File inputFile,
Map<DecodeHintType, Object> hints) throws Exception {

BufferedImage image;
LuminanceSource tempSource;
BinaryBitmap bitmap;
MultiFormatReader codeReader;
Result tempResult;
String finalResult;

if (inputFile == null || inputFile.getName().trim().isEmpty()) {
throw new IllegalArgumentException("File not found.");
}

try {

image = ImageIO.read(inputFile);

} catch (Exception e) {
throw new Exception (e.getMessage());
}

if (image == null) {
throw new IllegalArgumentException("Could not decode the image");
}

tempSource = new BufferedImageLuminanceSource(image);
bitmap = new BinaryBitmap(new HybridBinarizer(tempSource));
codeReader = new MultiFormatReader();

try {

if (hints != null && ! hints.isEmpty()) {
tempResult = codeReader.decode(bitmap, hints);
} else {
tempResult = codeReader.decode(bitmap);
}

finalResult = String.valueOf(tempResult.getText());

System.out.println(finalResult);

} catch (Exception e) {
e.printStackTrace();
throw new Exception("QRCodeUtil.decode Exception. " + e.toString());
}

}

The following error message appear's when reading an JPEG image

com.google.zxing.NotFoundException
java.lang.Exception: QRCodeUtil.decode Exception. com.google.zxing.NotFoundException
at cn.aws.testautomation.common.QRCodeUtil.deCodeQRCode(QRCodeUtil.java:128)
at cn.aws.testautomation.common.QRCodeUtil.main(QRCodeUtil.java:210)

Thank you and good day.

[Lachezar Dobrev]

It works if you use the TRY_HARDER hint.
JPEG is a lossy compression. It is possible, that it has added
artefacts that affect the algorithms.

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[Lachezar Dobrev]

The size of the images is different too.
Resizing the .jpg to the (nearly) same size (in pixels) also helps
and the bar-code can be found and read.