private QrDecodingResult decodeQR(BufferedImage image, int filenumber) {
// Create qr image from original for decoding
BufferedImage qrcorner = extractTopRightCornerForQR(image);
BufferedImage blackWhite =
new BufferedImage(
qrcorner.getWidth() / 2, qrcorner.getHeight() / 2, BufferedImage.TYPE_INT_RGB);
Graphics2D g2d = blackWhite.createGraphics();
g2d.drawImage(qrcorner, 0, 0, qrcorner.getWidth() / 2, qrcorner.getHeight() / 2, null);
g2d.dispose();
qrcorner = blackWhite;
QrDecodingResult decodingresult = new QrDecodingResult();
try {
// Decode QR
Result result = null;
Exception decodeException = null;
// Try to decode at least three times
int maxattempts = 3;
int attempt = 1;
while (attempt <= maxattempts) {
logger.debug("Attempt " + attempt);
try {
BinaryBitmap bitmap = getBitmapFromBufferedImage(qrcorner);
result = reader.decode(bitmap);
decodeException = null;
logger.debug("Success!");
break;
} catch (Exception e) {
decodeException = e;
if (debugcorners) {
try {
ImageIO.write(
(RenderedImage) qrcorner,
"jpg",
new File(
tempdir.getAbsolutePath() + "/corner" + filenumber + "_" + attempt + ".jpg"));
} catch (IOException ex) {
ex.printStackTrace();
}
}
}
attempt++;
com.jhlabs.image.MedianFilter filter = new MedianFilter();
BufferedImage newqrcorner =
new BufferedImage(
qrcorner.getWidth(), qrcorner.getHeight(), BufferedImage.TYPE_BYTE_GRAY);
filter.filter(qrcorner, newqrcorner);
qrcorner = newqrcorner;
}
if (decodeException != null) throw decodeException;
// Clean the output from the QR
decodingresult.setOutput(result.getText().replace(" ", "").trim());
// The image filename will be the output
decodingresult.setFilename(decodingresult.getOutput());
// Consistency checking
if (decodingresult.getFilename().length() == 0) {
decodingresult.setFilename("ERROR-EMPTYQR-" + (filenumber + 1));
} else {
String[] parts = decodingresult.getFilename().split("-");
// Now check if the QR string has five parts (which indicates it is an answer sheet)
if (parts.length == 5 && parts[4].trim().contains("BB")) {
decodingresult.setAttemptId(Integer.parseInt(parts[3]));
decodingresult.setAnswersheet(true);
}
// Now check if the QR string has a fourth component (image is rotated)
if (parts.length == 4 && parts[3].trim().contains("R")) {
decodingresult.setRotated(true);
}
// If everything looks well, parse the numbers from the decoded QR info
if (parts.length >= 3) {
// Parse the parts (any exception will be caught as an error)
decodingresult.setUserid(Integer.parseInt(parts[0]));
decodingresult.setCourseid(Integer.parseInt(parts[1]));
decodingresult.setExampage(Integer.parseInt(parts[2]));
// Set filename with the corresponding IDs
decodingresult.setFilename(
decodingresult.getUserid()
+ "-"
+ decodingresult.getCourseid()
+ "-"
+ decodingresult.getExampage());
// Processing was a success
decodingresult.setSuccess(true);
} else {
logger.error("QR contains invalid information");
decodingresult.setFilename("ERROR-INVALIDPARTSQR-" + (filenumber + 1));
}
}
} catch (NotFoundException e) {
decodingresult.setFilename("ERROR-NOTFOUND-" + (filenumber + 1));
} catch (ChecksumException e) {
decodingresult.setFilename("ERROR-CHECKSUM-" + (filenumber + 1));
} catch (FormatException e) {
decodingresult.setFilename("ERROR-CHECKSUM-" + (filenumber + 1));
} catch (Exception e) {
decodingresult.setFilename("ERROR-NULL-" + (filenumber + 1));
}
// Regardless of the result, the back-file name is the sames as the file with a b
decodingresult.setBackfilename(decodingresult.getFilename() + "b");
return decodingresult;
}
/* (non-Javadoc)
* @see java.lang.Runnable#run()
*/
@Override
public void run() {
// First decode the frontpage
this.qrResult = decodeQR(image, filenumber);
// If we couldn't find a code, but we have a backpage, we try processing it
if (!qrResult.isSuccess() && this.doubleside) {
QrDecodingResult qrresultback = decodeQR(backimage, filenumber);
// If the backpage contains a valid QR then it was flipped, we flip the front and backpages
if (qrresultback.isSuccess()) {
// Flip front and backpages
BufferedImage tmp = this.image;
this.image = this.backimage;
this.backimage = tmp;
// Replace decoding info with the backpage
qrResult = qrresultback;
}
}
float factor = 1200f / this.image.getWidth();
this.image = resizeImage(this.image, factor);
if (this.backimage != null) {
this.image = resizeImage(this.image, factor);
}
// If images were rotated, both are rotated
if (qrResult.isSuccess() && qrResult.isRotated()) {
this.image = rotateImage180(this.image);
if (this.doubleside) {
this.backimage = rotateImage180(this.backimage);
}
}
// All numbers are ok, now create the anonymous version of the page
this.anonymous = createAnonymousVersion(image);
if (this.doubleside) {
this.backanonymous = createAnonymousVersion(this.backimage);
}
this.success = qrResult.isSuccess();
this.rotated = qrResult.isRotated();
if (this.success && qrResult.isAnswersheet() && this.moodle.getOMRTemplate() != null) {
TreeMap<String, String> answers = new TreeMap<String, String>();
FormTemplate formTemplate = null;
try {
File omrtemplatefile = new File(this.moodle.getOMRTemplate());
formTemplate = new FormTemplate(omrtemplatefile);
FormTemplate filledForm = new FormTemplate(qrResult.getFilename(), formTemplate);
filledForm.findCorners(
anonymous, this.moodle.getOMRthreshold(), this.moodle.getOMRdensity());
filledForm.findPoints(
anonymous,
this.moodle.getOMRthreshold(),
this.moodle.getOMRdensity(),
this.moodle.getOMRshapeSize());
for (String key : filledForm.getFields().keySet()) {
FormField ff = filledForm.getField(key);
answers.put(key, ff.getValues());
}
qrResult.setAnswers(answers);
} catch (Exception e) {
logger.error("Problem with the OMR template");
e.printStackTrace();
}
}
// Now write images as files
try {
ImageIO.write(
(RenderedImage) image,
imageExtension,
new File(
tempdir.getAbsolutePath() + "/" + qrResult.getFilename() + "." + imageExtension));
ImageIO.write(
(RenderedImage) anonymous,
imageExtension,
new File(
tempdir.getAbsolutePath() + "/" + qrResult.getFilename() + "_a." + imageExtension));
if (doubleside) {
ImageIO.write(
(RenderedImage) backimage,
imageExtension,
new File(
tempdir.getAbsolutePath()
+ "/"
+ qrResult.getBackfilename()
+ "."
+ imageExtension));
ImageIO.write(
(RenderedImage) backanonymous,
imageExtension,
new File(
tempdir.getAbsolutePath()
+ "/"
+ qrResult.getBackfilename()
+ "_a."
+ imageExtension));
}
} catch (IOException e) {
e.printStackTrace();
}
}
