Meziantou.FrameworkBarcodeDecoder Class
Reads linear barcodes from their modules or from scan lines: Code 39, Code 93, Code 128, GS1-128, EAN-8, EAN-13, UPC-A, UPC-E (with their add-ons), Codabar, ITF, and GS1 DataBar (Omnidirectional, Stacked, Stacked Omnidirectional, Limited, Expanded and Expanded Stacked).
public static class BarcodeDecoderRemarks
The decoder works on the widths of the bars and spaces, not on pixels. To read the barcodes of an image, use the ReadBarcodes methods of the Meziantou.Framework.Imaging.Barcodes package, which scan its pixels.
Methods
| Name | Description |
|---|---|
| Decode(Barcode) | Reads a barcode. |
| Decode(bool[,]) | Reads a barcode from its modules. |
| DecodeScanLines(IReadOnlyList<int[]>) | Reads the linear barcodes that scan lines cross. |
| TryDecode(bool[,], BarcodeDecodeResult?) | Tries to read a barcode from its modules. |
Decode overloads
Decode(Barcode)
BarcodeDecoder.csReads a barcode.
public static BarcodeDecodeResult Decode(Barcode barcode)Parameters
barcodeBarcode- The barcode.
Returns
BarcodeDecodeResult The barcode that was read.
Exceptions
ArgumentNullExceptionbarcodeisnull.
Example
var barcode = Barcode.CreateCode128("SKU-123456");
var result = BarcodeDecoder.Decode(barcode);
Assert.Equal((BarcodeType.Code128, "SKU-123456"), (result.Type, result.Text));Decode(bool[,])
BarcodeDecoder.csReads a barcode from its modules.
public static BarcodeDecodeResult Decode(bool[,] modules)Parameters
modulesbool[,]- The modules,
truefor dark, indexed by row then column, without quiet zone: one row for a linear barcode, the rows of a stacked GS1 DataBar symbol (separators included) for a stacked one.
Returns
BarcodeDecodeResult The barcode that was read.
Exceptions
ArgumentNullExceptionmodulesisnull.FormatException- The modules are not a barcode that the decoder can read.
DecodeScanLines(IReadOnlyList<int[]>)
BarcodeDecoder.csReads the linear barcodes that scan lines cross.
public static IReadOnlyList<BarcodeDecodeResult> DecodeScanLines(IReadOnlyList<int[]> scanLines)Parameters
scanLinesIReadOnlyList<int[]>- The scan lines: each is the widths of its alternating light and dark runs, in any unit (pixels), starting with a light run (which can be 0 wide). The lines of a stacked GS1 DataBar symbol are in order from the top.
Returns
IReadOnlyList<BarcodeDecodeResult> The barcodes found, each once even when several lines cross it.
Exceptions
ArgumentNullExceptionscanLinesisnullor containsnull.
Remarks
A barcode can be read from either end, and must have its quiet zones. A symbology without check character, such as ITF or Codabar, can be misread from a damaged line: require that several lines agree (BarcodeDecodeResult.FirstScanLine and BarcodeDecodeResult.LastScanLine).
Example
// A scan line: the widths of its light and dark runs, starting with a light run, here 3 pixels per module
var barcode = Barcode.CreateEan13("590123412345");
var runs = new List<int> { 30 };
for (var column = 0; column < barcode.Width; column++)
{
if (barcode[0, column] != (runs.Count % 2 == 0))
{
runs.Add(0);
}
runs[^1] += 3;
}
// The quiet zone after the last bar
runs.Add(30);
var results = BarcodeDecoder.DecodeScanLines([runs.ToArray()]);
var result = Assert.Single(results);
Assert.Equal((BarcodeType.Ean13, "5901234123457"), (result.Type, result.Text));
Assert.Equal((30, 30 + (95 * 3)), (result.Start, result.End));TryDecode(bool[,], BarcodeDecodeResult?)
BarcodeDecoder.csTries to read a barcode from its modules.
public static bool TryDecode(bool[,] modules, out BarcodeDecodeResult? result)Parameters
modulesbool[,]- The modules,
truefor dark, indexed by row then column, without quiet zone. resultBarcodeDecodeResult?- When this method returns
true, the barcode that was read.
Returns
bool true if a barcode could be read; otherwise, false.
Exceptions
ArgumentNullExceptionmodulesisnull.