decode static method

DecoderResult decode(BitMatrix image, ResultPoint? imageTopLeft, ResultPoint? imageBottomLeft, ResultPoint? imageTopRight, ResultPoint? imageBottomRight, int minCodewordWidth, int maxCodewordWidth,)

Implementation

static DecoderResult decode(
  BitMatrix image,
  ResultPoint? imageTopLeft,
  ResultPoint? imageBottomLeft,
  ResultPoint? imageTopRight,
  ResultPoint? imageBottomRight,
  int minCodewordWidth,
  int maxCodewordWidth,
) {
  BoundingBox boundingBox = BoundingBox(
    image,
    imageTopLeft,
    imageBottomLeft,
    imageTopRight,
    imageBottomRight,
  );
  DetectionResultRowIndicatorColumn? leftRowIndicatorColumn;
  DetectionResultRowIndicatorColumn? rightRowIndicatorColumn;
  DetectionResult? detectionResult;
  for (bool firstPass = true;; firstPass = false) {
    if (imageTopLeft != null) {
      leftRowIndicatorColumn = _getRowIndicatorColumn(
        image,
        boundingBox,
        imageTopLeft,
        true,
        minCodewordWidth,
        maxCodewordWidth,
      );
    }
    if (imageTopRight != null) {
      rightRowIndicatorColumn = _getRowIndicatorColumn(
        image,
        boundingBox,
        imageTopRight,
        false,
        minCodewordWidth,
        maxCodewordWidth,
      );
    }
    detectionResult = _merge(leftRowIndicatorColumn, rightRowIndicatorColumn);
    if (detectionResult == null) {
      throw NotFoundException.instance;
    }
    final resultBox = detectionResult.boundingBox;
    if (firstPass &&
        resultBox != null &&
        (resultBox.minY < boundingBox.minY ||
            resultBox.maxY > boundingBox.maxY)) {
      boundingBox = resultBox;
    } else {
      break;
    }
  }
  detectionResult.boundingBox = boundingBox;
  final maxBarcodeColumn = detectionResult.barcodeColumnCount + 1;
  detectionResult.setDetectionResultColumn(0, leftRowIndicatorColumn);
  detectionResult.setDetectionResultColumn(
    maxBarcodeColumn,
    rightRowIndicatorColumn,
  );

  final leftToRight = leftRowIndicatorColumn != null;
  for (int barcodeColumnCount = 1;
      barcodeColumnCount <= maxBarcodeColumn;
      barcodeColumnCount++) {
    final barcodeColumn = leftToRight
        ? barcodeColumnCount
        : maxBarcodeColumn - barcodeColumnCount;
    if (detectionResult.getDetectionResultColumn(barcodeColumn) != null) {
      // This will be the case for the opposite row indicator column, which doesn't need to be decoded again.
      continue;
    }
    late DetectionResultColumn detectionResultColumn;
    if (barcodeColumn == 0 || barcodeColumn == maxBarcodeColumn) {
      detectionResultColumn =
          DetectionResultRowIndicatorColumn(boundingBox, barcodeColumn == 0);
    } else {
      detectionResultColumn = DetectionResultColumn(boundingBox);
    }
    detectionResult.setDetectionResultColumn(
      barcodeColumn,
      detectionResultColumn,
    );
    int startColumn = -1;
    int previousStartColumn = startColumn;
    // TODO start at a row for which we know the start position, then detect upwards and downwards from there.
    for (int imageRow = boundingBox.minY;
        imageRow <= boundingBox.maxY;
        imageRow++) {
      startColumn = _getStartColumn(
        detectionResult,
        barcodeColumn,
        imageRow,
        leftToRight,
      );
      if (startColumn < 0 || startColumn > boundingBox.maxX) {
        if (previousStartColumn == -1) {
          continue;
        }
        startColumn = previousStartColumn;
      }
      final codeword = _detectCodeword(
        image,
        boundingBox.minX,
        boundingBox.maxX,
        leftToRight,
        startColumn,
        imageRow,
        minCodewordWidth,
        maxCodewordWidth,
      );
      if (codeword != null) {
        detectionResultColumn.setCodeword(imageRow, codeword);
        previousStartColumn = startColumn;
        minCodewordWidth = math.min(minCodewordWidth, codeword.width);
        maxCodewordWidth = math.max(maxCodewordWidth, codeword.width);
      }
    }
  }
  return _createDecoderResult(detectionResult);
}