Work with symbology types

Working with symbology types in recognition

Configuring DecodeType values correctly helps you:

  • improve performance by narrowing down the search space,
  • reduce false positives by filtering out unexpected symbologies,
  • make your intent explicit in the code and tests,
  • document which barcode formats your application actually supports.

This article shows how to:

  1. Use symbology configuration strategies (single type, small sets, grouped types, discovery).
  2. Work with common 1D symbologies (Code 128, Code 39, EAN, UPC, Codabar, ITF-14).
  3. Work with 2D symbologies (QR, Micro QR, Data Matrix, GS1 Data Matrix, PDF417, Macro PDF417, Aztec).
  4. Work with postal barcodes.
  5. Recognize multiple barcodes in one image.

All examples are based on the sample classes:

In the snippets below, helper methods such as ExampleAssist.checkOrCreateImage,
ExampleAssist.pathCombine, ExampleAssist.assertRecognized, and ExampleAssist.assertNotRecognized come from the test infrastructure and are used to generate fixtures and verify results.

1. Symbology configuration strategies

This section focuses on how to configure DecodeType, not on individual barcode formats.

1.1 Using a single explicit symbology

If you know exactly which symbology you expect, the best option is to pass a single explicit DecodeType to BarCodeReader.
This is both the fastest and the safest configuration.

The example below shows how to recognize a Code 128 symbol using DecodeType.CODE_128 only:

String imagePath = getFullPath(FILE_C128);

BarCodeReader barCodeReader =
        new BarCodeReader(imagePath, DecodeType.CODE_128);

ExampleAssist.assertRecognized(
        barCodeReader,
        FILE_C128,
        1,
        DecodeType.CODE_128
);

Use this pattern when:

  • the business process strictly defines the symbology (for example, Code 128 for internal IDs),
  • performance is important and you want to avoid checking other types,
  • you want to minimize the chance of false positives from similar barcodes.

The same approach applies to other formats, such as DecodeType.EAN_13, DecodeType.QR, DecodeType.DATA_MATRIX, and so on.

1.2 Using the “most common” set

Sometimes you do not know the exact symbology, but you still want to keep the search limited to popular types.

In this case, use the grouped type DecodeType.MOST_COMMON_TYPES.
Aspose.BarCode will try a curated set of commonly used symbologies:

String imagePath = getFullPath(FILE_QR);

BarCodeReader barCodeReader =
        new BarCodeReader(imagePath, DecodeType.MOST_COMMON_TYPES);

ExampleAssist.assertRecognized(
        barCodeReader,
        FILE_QR,
        1,
        DecodeType.QR
);

This configuration is useful when:

  • your system accepts several common barcode types,
  • the input data is heterogeneous but still limited to typical retail or logistics formats.

1.3 Using grouped 1D and 2D types

Aspose.BarCode also provides grouped DecodeType values for all 1D and all 2D symbologies:

  • DecodeType.TYPES_1D – restricts recognition to linear (1D) codes,
  • DecodeType.TYPES_2D – restricts recognition to 2D codes such as QR, Data Matrix, PDF417, Aztec.

Example: recognize a Code 128 barcode with all 1D types allowed:

String fileName = "types_1D_barcodes.png";

ExampleAssist.checkOrCreateImage(FOLDER, fileName, fullPath -> {
    BarcodeGenerator barcodeGenerator =
            new BarcodeGenerator(EncodeTypes.CODE_128, "1D-SET");
    barcodeGenerator.save(fullPath, BarCodeImageFormat.PNG);
});

String imagePath = ExampleAssist.pathCombine(FOLDER, fileName);
BarCodeReader barCodeReader =
        new BarCodeReader(imagePath, DecodeType.TYPES_1D);

ExampleAssist.assertRecognized(barCodeReader, fileName, 1, DecodeType.CODE_128);

Example: recognize a Data Matrix barcode when all 2D types are allowed:

String fileName = "types_2D_barcodes.png";

ExampleAssist.checkOrCreateImage(FOLDER, fileName, fullPath -> {
    BarcodeGenerator barcodeGenerator =
            new BarcodeGenerator(EncodeTypes.DATA_MATRIX, "2D-SET");
    barcodeGenerator.save(fullPath, BarCodeImageFormat.PNG);
});

String imagePath = ExampleAssist.pathCombine(FOLDER, fileName);
BarCodeReader barCodeReader =
        new BarCodeReader(imagePath, DecodeType.TYPES_2D);

ExampleAssist.assertRecognized(barCodeReader, fileName, 1, DecodeType.DATA_MATRIX);

Use these grouped types when you know your application only uses 1D or only 2D barcodes.

1.4 Passing multiple explicit symbologies

You can configure BarCodeReader to use a small explicit set of symbologies.
This combines the control of explicit types with more flexibility than a single type.

The test fixture contains a mixed image with a QR Code and a Code 128 symbol placed side by side.
The following snippet shows how to recognize both of them by passing DecodeType.QR and DecodeType.CODE_128:

String imagePath = getFullPath(FILE_MIX);

BarCodeReader barCodeReader =
        new BarCodeReader(imagePath, DecodeType.QR, DecodeType.CODE_128);

BarCodeResult[] results = barCodeReader.readBarCodes();

Assert.assertTrue(results.length >= 2, "Expected at least QR + Code128");

boolean hasQR = ExampleAssist.hasDecodeType(results, DecodeType.QR);
boolean hasC128 = ExampleAssist.hasDecodeType(results, DecodeType.CODE_128);

Assert.assertTrue(hasQR && hasC128, "Mixed image must contain QR and Code128");

Use this approach when:

  • your application supports a limited list of types (for example, QR and Code 128),
  • you want to avoid the overhead of ALL_SUPPORTED_TYPES,
  • you want more control than MOST_COMMON_TYPES provides.

1.5 Defining a custom subset with setBarCodeReadType

In addition to constructor parameters, you can configure a custom subset of symbologies at runtime using setBarCodeReadType(...).

In the following example, the reader is limited to three symbologies: Code 128, QR, and Data Matrix:

String fileName = "specific_types.png";

ExampleAssist.checkOrCreateImage(FOLDER, fileName, fullPath -> {
    BarcodeGenerator barcodeGenerator =
            new BarcodeGenerator(EncodeTypes.DATA_MATRIX, "Specific types");
    barcodeGenerator.save(fullPath, BarCodeImageFormat.PNG);
});

String imagePath = ExampleAssist.pathCombine(FOLDER, fileName);
BarCodeReader barCodeReader =
        new BarCodeReader(imagePath, DecodeType.ALL_SUPPORTED_TYPES);

barCodeReader.setBarCodeReadType(
        DecodeType.CODE_128,
        DecodeType.QR,
        DecodeType.DATA_MATRIX
);

ExampleAssist.assertRecognized(barCodeReader, fileName, 1, DecodeType.DATA_MATRIX);

Use this pattern when:

  • your application supports a known subset of symbologies,
  • you want to avoid checking all others,
  • you need to configure the subset dynamically.

1.6 Using all supported types for discovery

For exploratory scenarios, you may want to detect any supported symbology present in the image.
This is the broadest search and therefore the slowest and most permissive.

Use DecodeType.ALL_SUPPORTED_TYPES:

String imagePath = getFullPath(FILE_EAN13);

BarCodeReader barCodeReader =
        new BarCodeReader(imagePath, DecodeType.ALL_SUPPORTED_TYPES);

ExampleAssist.assertRecognized(
        barCodeReader,
        FILE_EAN13,
        1,
        DecodeType.EAN_13
);

Typical use cases:

  • diagnostics and debugging when you are not sure which symbology is printed,
  • tools that must handle arbitrary barcodes without prior knowledge,
  • migrating legacy systems where symbology usage is unknown.

1.7 Filtering to avoid false positives

Restricting DecodeType not only improves speed, but also helps reject invalid images.

The following example intentionally misconfigures the reader:
it tries to read a Code 128 barcode while allowing only DecodeType.QR.
In this case you expect zero results:

String imagePath = getFullPath(FILE_C128);

BarCodeReader barCodeReader =
        new BarCodeReader(imagePath, DecodeType.QR);

ExampleAssist.assertNotRecognized(barCodeReader, FILE_C128);

This pattern is useful when:

  • you want to be strict about accepted symbologies,
  • you treat any result of an unexpected type as a potential false positive,
  • you implement validation logic in tests or QA tools.

1.8 Using an exact type for 2D barcodes such as Data Matrix

For 2D barcodes like Data Matrix, it is often safer to use the exact DecodeType.
When you already know that the image contains a specific 2D barcode type (for example, Data Matrix), specifying the exact DecodeType lets the engine skip other 2D symbologies, which improves performance and can make recognition more robust on low-quality images.

The example below uses DecodeType.DATA_MATRIX to recognize a Data Matrix symbol:

String imagePath = getFullPath(FILE_DM);

BarCodeReader barCodeReader =
        new BarCodeReader(imagePath, DecodeType.DATA_MATRIX);

ExampleAssist.assertRecognized(
        barCodeReader,
        FILE_DM,
        1,
        DecodeType.DATA_MATRIX
);

This approach is recommended when:

  • your process standardizes on a specific 2D symbology (for example Data Matrix on labels),
  • you use GS1 or other structured data encoded in 2D barcodes,
  • you want predictable behavior and clear expectations in tests.

2. Examples for common 1D symbologies

This section shows how to apply the configuration strategies to specific 1D formats using ChooseRecognitionSymbology.

In production code you often know exactly which 1D symbology you expect: Code 128 for logistics labels, EAN/UPC for retail, ITF-14 for cartons, and so on.
In such cases, pass the exact DecodeType to BarCodeReader.

2.1 Code 128

String fileName = "code128.png";

ExampleAssist.checkOrCreateImage(FOLDER, fileName, fullPath -> {
    BarcodeGenerator barcodeGenerator =
            new BarcodeGenerator(EncodeTypes.CODE_128, "123456789");
    barcodeGenerator.save(fullPath, BarCodeImageFormat.PNG);
});

String imagePath = ExampleAssist.pathCombine(FOLDER, fileName);
BarCodeReader barCodeReader = new BarCodeReader(imagePath, DecodeType.CODE_128);
ExampleAssist.assertRecognized(barCodeReader, fileName, 1, DecodeType.CODE_128);

Use this pattern when you work with logistics labels, internal IDs, or other generic Code 128 data and want fast, precise recognition.

2.2 Code 39 and Code 39 Full ASCII

String fileName = "code39.png";

ExampleAssist.checkOrCreateImage(FOLDER, fileName, fullPath -> {
    BarcodeGenerator barcodeGenerator =
            new BarcodeGenerator(EncodeTypes.CODE_39, "CODE39-123");
    barcodeGenerator.save(fullPath, BarCodeImageFormat.PNG);
});

String imagePath = ExampleAssist.pathCombine(FOLDER, fileName);
BarCodeReader barCodeReader = new BarCodeReader(imagePath, DecodeType.CODE_39);
ExampleAssist.assertRecognized(barCodeReader, fileName, 1, DecodeType.CODE_39);

String fileName = "code39_full_ascii.png";

ExampleAssist.checkOrCreateImage(FOLDER, fileName, fullPath -> {
    BarcodeGenerator barcodeGenerator =
            new BarcodeGenerator(EncodeTypes.CODE_39_FULL_ASCII, "Full+ASCII/%$-123");
    barcodeGenerator.save(fullPath, BarCodeImageFormat.PNG);
});

String imagePath = ExampleAssist.pathCombine(FOLDER, fileName);
BarCodeReader barCodeReader =
        new BarCodeReader(imagePath, DecodeType.CODE_39_FULL_ASCII);
ExampleAssist.assertRecognized(barCodeReader, fileName, 1, DecodeType.CODE_39_FULL_ASCII);

Use Code 39 Full ASCII when you need the extended character set beyond the basic Code 39 alphabet.

2.3 EAN-13 and EAN-13 with supplement

String fileName = "ean13.png";

ExampleAssist.checkOrCreateImage(FOLDER, fileName, fullPath -> {
    BarcodeGenerator barcodeGenerator =
            new BarcodeGenerator(EncodeTypes.EAN_13, "5901234123457");
    barcodeGenerator.save(fullPath, BarCodeImageFormat.PNG);
});

String imagePath = ExampleAssist.pathCombine(FOLDER, fileName);
BarCodeReader barCodeReader = new BarCodeReader(imagePath, DecodeType.EAN_13);
ExampleAssist.assertRecognized(barCodeReader, fileName, 1, DecodeType.EAN_13);

String fileName = "ean13_supplement.png";

ExampleAssist.checkOrCreateImage(FOLDER, fileName, fullPath -> {
    BarcodeGenerator barcodeGenerator =
            new BarcodeGenerator(EncodeTypes.EAN_13, "5901234123457");
    barcodeGenerator.getParameters().getBarcode().getSupplement().setSupplementData("12345");
    barcodeGenerator.save(fullPath, BarCodeImageFormat.PNG);
});

String imagePath = ExampleAssist.pathCombine(FOLDER, fileName);
BarCodeReader barCodeReader = new BarCodeReader(imagePath, DecodeType.EAN_13);
barCodeReader.getBarcodeSettings().setDetectEncoding(true);
ExampleAssist.assertRecognized(barCodeReader, fileName, 1, DecodeType.EAN_13);

EAN-13 with a 2- or 5-digit supplement is common for magazines and books.
The main symbology is still EAN-13, so DecodeType.EAN_13 is used.

2.4 EAN-8

String fileName = "ean8.png";

ExampleAssist.checkOrCreateImage(FOLDER, fileName, fullPath -> {
    BarcodeGenerator barcodeGenerator =
            new BarcodeGenerator(EncodeTypes.EAN_8, "12345670");
    barcodeGenerator.save(fullPath, BarCodeImageFormat.PNG);
});

String imagePath = ExampleAssist.pathCombine(FOLDER, fileName);
BarCodeReader barCodeReader = new BarCodeReader(imagePath, DecodeType.EAN_8);
ExampleAssist.assertRecognized(barCodeReader, fileName, 1, DecodeType.EAN_8);

Use EAN-8 for small products where a full EAN-13 symbol would not fit.

2.5 UPC-A and UPC-E

String fileName = "upca.png";

ExampleAssist.checkOrCreateImage(FOLDER, fileName, fullPath -> {
    BarcodeGenerator barcodeGenerator =
            new BarcodeGenerator(EncodeTypes.UPCA, "123456789012");
    barcodeGenerator.save(fullPath, BarCodeImageFormat.PNG);
});

String imagePath = ExampleAssist.pathCombine(FOLDER, fileName);
BarCodeReader barCodeReader = new BarCodeReader(imagePath, DecodeType.UPCA);
ExampleAssist.assertRecognized(barCodeReader, fileName, 1, DecodeType.UPCA);

String fileName = "upce.png";

ExampleAssist.checkOrCreateImage(FOLDER, fileName, fullPath -> {
    BarcodeGenerator barcodeGenerator =
            new BarcodeGenerator(EncodeTypes.UPCE, "123456");
    barcodeGenerator.save(fullPath, BarCodeImageFormat.PNG);
});

String imagePath = ExampleAssist.pathCombine(FOLDER, fileName);
BarCodeReader barCodeReader = new BarCodeReader(imagePath, DecodeType.UPCE);
ExampleAssist.assertRecognized(barCodeReader, fileName, 1, DecodeType.UPCE);

UPC-A and UPC-E are widely used in North America for retail items.
Use the matching DecodeType for the symbology you expect on your labels.

2.6 Codabar

String fileName = "codabar.png";

ExampleAssist.checkOrCreateImage(FOLDER, fileName, fullPath -> {
    BarcodeGenerator barcodeGenerator =
            new BarcodeGenerator(EncodeTypes.CODABAR, "A123456A");
    barcodeGenerator.save(fullPath, BarCodeImageFormat.PNG);
});

String imagePath = ExampleAssist.pathCombine(FOLDER, fileName);
BarCodeReader barCodeReader = new BarCodeReader(imagePath, DecodeType.CODABAR);
ExampleAssist.assertRecognized(barCodeReader, fileName, 1, DecodeType.CODABAR);

Codabar is often used in logistics, libraries, and medical applications where start/stop characters carry additional meaning.

2.7 ITF-14

String fileName = "itf14.png";

ExampleAssist.checkOrCreateImage(FOLDER, fileName, fullPath -> {
    BarcodeGenerator barcodeGenerator =
            new BarcodeGenerator(EncodeTypes.ITF_14, "12345678901231");
    barcodeGenerator.save(fullPath, BarCodeImageFormat.PNG);
});

String imagePath = ExampleAssist.pathCombine(FOLDER, fileName);
BarCodeReader barCodeReader = new BarCodeReader(imagePath, DecodeType.ITF_14);
ExampleAssist.assertRecognized(barCodeReader, fileName, 1, DecodeType.ITF_14);

ITF-14 is used for shipping containers and outer packaging, usually encoding GTIN-14 values.

3. Examples for 2D symbologies

For 2D barcodes you also choose specific DecodeType values.
This section shows basic patterns for QR, Micro QR, Data Matrix, GS1 Data Matrix, PDF417, Macro PDF417, and Aztec.

3.1 QR Code and Micro QR

String fileName = "qrcode.png";

ExampleAssist.checkOrCreateImage(FOLDER, fileName, fullPath -> {
    BarcodeGenerator barcodeGenerator =
            new BarcodeGenerator(EncodeTypes.QR, "Hello QR");
    barcodeGenerator.save(fullPath, BarCodeImageFormat.PNG);
});

String imagePath = ExampleAssist.pathCombine(FOLDER, fileName);
BarCodeReader barCodeReader = new BarCodeReader(imagePath, DecodeType.QR);
ExampleAssist.assertRecognized(barCodeReader, fileName, 1, DecodeType.QR);

String fileName = "microqr.png";

ExampleAssist.checkOrCreateImage(FOLDER, fileName, fullPath -> {
    BarcodeGenerator barcodeGenerator =
            new BarcodeGenerator(EncodeTypes.MICRO_QR, "MQR");
    barcodeGenerator.save(fullPath, BarCodeImageFormat.PNG);
});

String imagePath = ExampleAssist.pathCombine(FOLDER, fileName);
BarCodeReader barCodeReader = new BarCodeReader(imagePath, DecodeType.MICRO_QR);
ExampleAssist.assertRecognized(barCodeReader, fileName, 1, DecodeType.MICRO_QR);

Micro QR is useful when you have very little space and short payloads.

3.2 QR with high-quality settings (damaged or low-quality images)

String fileName = "qrcode_damaged.png";

ExampleAssist.checkOrCreateImage(FOLDER, fileName, fullPath -> {
    BarcodeGenerator barcodeGenerator =
            new BarcodeGenerator(EncodeTypes.QR, "Damaged?");
    barcodeGenerator.save(fullPath, BarCodeImageFormat.PNG);
});

String imagePath = ExampleAssist.pathCombine(FOLDER, fileName);
BarCodeReader barCodeReader = new BarCodeReader(imagePath, DecodeType.QR);
barCodeReader.setQualitySettings(QualitySettings.getHighQuality());
ExampleAssist.assertRecognized(barCodeReader, fileName, 1, DecodeType.QR);

QualitySettings.getHighQuality() enables more aggressive image processing and can improve recognition of noisy or partially damaged symbols at the cost of performance.

3.3 Data Matrix and GS1 Data Matrix

String fileName = "datamatrix.png";

ExampleAssist.checkOrCreateImage(FOLDER, fileName, fullPath -> {
    BarcodeGenerator barcodeGenerator =
            new BarcodeGenerator(EncodeTypes.DATA_MATRIX, "DMATRIX-12345");
    barcodeGenerator.save(fullPath, BarCodeImageFormat.PNG);
});

String imagePath = ExampleAssist.pathCombine(FOLDER, fileName);
BarCodeReader barCodeReader = new BarCodeReader(imagePath, DecodeType.DATA_MATRIX);
ExampleAssist.assertRecognized(barCodeReader, fileName, 1, DecodeType.DATA_MATRIX);

String fileName = "datamatrix_gs1.png";

ExampleAssist.checkOrCreateImage(FOLDER, fileName, fullPath -> {
    String gs1CodeText = "(01)12345678901231(10)ABCD1234";
    BarcodeGenerator barcodeGenerator =
            new BarcodeGenerator(EncodeTypes.GS_1_DATA_MATRIX, gs1CodeText);
    barcodeGenerator.save(fullPath, BarCodeImageFormat.PNG);
});

String imagePath = ExampleAssist.pathCombine(FOLDER, fileName);
BarCodeReader barCodeReader =
        new BarCodeReader(imagePath, DecodeType.GS_1_DATA_MATRIX);
ExampleAssist.assertRecognized(barCodeReader, fileName, 1, DecodeType.GS_1_DATA_MATRIX);

Use DecodeType.GS_1_DATA_MATRIX when you expect GS1 AIs with FNC1 separators inside the symbol.

3.4 PDF417 and Macro PDF417

String fileName = "pdf417.png";

ExampleAssist.checkOrCreateImage(FOLDER, fileName, fullPath -> {
    BarcodeGenerator barcodeGenerator =
            new BarcodeGenerator(EncodeTypes.PDF_417, "PDF417 sample");
    barcodeGenerator.save(fullPath, BarCodeImageFormat.PNG);
});

String imagePath = ExampleAssist.pathCombine(FOLDER, fileName);
BarCodeReader barCodeReader = new BarCodeReader(imagePath, DecodeType.PDF_417);
ExampleAssist.assertRecognized(barCodeReader, fileName, 1, DecodeType.PDF_417);

String fileName = "pdf417_macro.png";

ExampleAssist.checkOrCreateImage(FOLDER, fileName, fullPath -> {
    BarcodeGenerator barcodeGenerator =
            new BarcodeGenerator(EncodeTypes.MACRO_PDF_417, "Macro segment");
    barcodeGenerator.save(fullPath, BarCodeImageFormat.PNG);
});

String imagePath = ExampleAssist.pathCombine(FOLDER, fileName);
BarCodeReader barCodeReader =
        new BarCodeReader(imagePath, DecodeType.MACRO_PDF_417);
ExampleAssist.assertRecognized(barCodeReader, fileName, 1, DecodeType.MACRO_PDF_417);

Use Macro PDF417 when your payload is split across multiple PDF417 symbols and you need macro metadata (file ID, segment index, segments count).

3.5 Aztec

String fileName = "aztec.png";

ExampleAssist.checkOrCreateImage(FOLDER, fileName, fullPath -> {
    BarcodeGenerator barcodeGenerator =
            new BarcodeGenerator(EncodeTypes.AZTEC, "AZTEC-OK");
    barcodeGenerator.save(fullPath, BarCodeImageFormat.PNG);
});

String imagePath = ExampleAssist.pathCombine(FOLDER, fileName);
BarCodeReader barCodeReader = new BarCodeReader(imagePath, DecodeType.AZTEC);
ExampleAssist.assertRecognized(barCodeReader, fileName, 1, DecodeType.AZTEC);

Aztec codes are common in transportation, tickets, and documents where high information density and robust reading are required.

3.6 GS1-128 only

String fileName = "gs1_128.png";

ExampleAssist.checkOrCreateImage(FOLDER, fileName, fullPath -> {
    String gs1CodeText = "(01)09501101530008(17)251231(10)BATCH-42";
    BarcodeGenerator barcodeGenerator =
            new BarcodeGenerator(EncodeTypes.GS_1_CODE_128, gs1CodeText);
    barcodeGenerator.getParameters().getBarcode().getXDimension().setPixels(2);
    barcodeGenerator.getParameters().getBarcode().getBarHeight().setPixels(60);
    barcodeGenerator.save(fullPath, BarCodeImageFormat.PNG);
});

String imagePath = ExampleAssist.pathCombine(FOLDER, fileName);
BarCodeReader barCodeReader =
        new BarCodeReader(imagePath, DecodeType.GS_1_CODE_128);
ExampleAssist.assertRecognized(barCodeReader, fileName, 1, DecodeType.GS_1_CODE_128);

Use DecodeType.GS_1_CODE_128 when you expect GS1 application identifiers encoded in a Code 128 symbol.

4. Postal barcodes

Postal symbologies have dedicated DecodeType values.
The examples below show how to generate and recognize POSTNET, PLANET, and Australia Post barcodes.

4.1 POSTNET

String fileName = "postnet.png";

ExampleAssist.checkOrCreateImage(FOLDER, fileName, fullPath -> {
    BarcodeGenerator barcodeGenerator =
            new BarcodeGenerator(EncodeTypes.POSTNET, "12345");
    barcodeGenerator.save(fullPath, BarCodeImageFormat.PNG);
});

String imagePath = ExampleAssist.pathCombine(FOLDER, fileName);
BarCodeReader barCodeReader = new BarCodeReader(imagePath, DecodeType.POSTNET);
ExampleAssist.assertRecognized(barCodeReader, fileName, 1, DecodeType.POSTNET);

4.2 PLANET

String fileName = "planet.png";

ExampleAssist.checkOrCreateImage(FOLDER, fileName, fullPath -> {
    BarcodeGenerator barcodeGenerator =
            new BarcodeGenerator(EncodeTypes.PLANET, "401234567890");
    barcodeGenerator.save(fullPath, BarCodeImageFormat.PNG);
});

String imagePath = ExampleAssist.pathCombine(FOLDER, fileName);
BarCodeReader barCodeReader = new BarCodeReader(imagePath, DecodeType.PLANET);
ExampleAssist.assertRecognized(barCodeReader, fileName, 1, DecodeType.PLANET);

4.3 Australia Post

String fileName = "australia_post.png";

ExampleAssist.checkOrCreateImage(FOLDER, fileName, fullPath -> {
    String codeText = "11" + "12345678";
    BarcodeGenerator barcodeGenerator =
            new BarcodeGenerator(EncodeTypes.AUSTRALIA_POST, codeText);
    barcodeGenerator.save(fullPath, BarCodeImageFormat.PNG);
});

String imagePath = ExampleAssist.pathCombine(FOLDER, fileName);
BarCodeReader barCodeReader =
        new BarCodeReader(imagePath, DecodeType.AUSTRALIA_POST);
ExampleAssist.assertRecognized(barCodeReader, fileName, 1, DecodeType.AUSTRALIA_POST);

Use postal-specific DecodeType values when integrating with national postal systems.

5. Mixed and multiple barcodes in one image

You can also recognize images that contain more than one barcode.

In this scenario you typically use a broader DecodeType (for example ALL_SUPPORTED_TYPES or MOST_COMMON_TYPES)
and then inspect each BarCodeResult returned by readBarCodes().

The following example uses two symbols (Code 128 and QR) drawn on a single canvas:

String fileName = "multi.png";

String tempCode128Path = ExampleAssist.pathCombine(FOLDER, "tmp_multi_code128.png");
String tempQrPath = ExampleAssist.pathCombine(FOLDER, "tmp_multi_qr.png");

BarcodeGenerator barcodeGenerator1 =
        new BarcodeGenerator(EncodeTypes.CODE_128, "MULTI-1-C128");
barcodeGenerator1.getParameters().getBarcode().getXDimension().setPixels(2);
barcodeGenerator1.getParameters().getBarcode().getBarHeight().setPixels(60);
barcodeGenerator1.save(tempCode128Path, BarCodeImageFormat.PNG);

BarcodeGenerator barcodeGenerator2 =
        new BarcodeGenerator(EncodeTypes.QR, "MULTI-2-QR");
barcodeGenerator2.getParameters().getBarcode().getXDimension().setPixels(4);
barcodeGenerator2.save(tempQrPath, BarCodeImageFormat.PNG);

BufferedImage leftImage = ImageIO.read(java.nio.file.Paths.get(tempCode128Path).toFile());
BufferedImage rightImage = ImageIO.read(java.nio.file.Paths.get(tempQrPath).toFile());

int gap = 20;
int width = leftImage.getWidth() + gap + rightImage.getWidth();
int height = Math.max(leftImage.getHeight(), rightImage.getHeight());

BufferedImage canvas = new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB);
Graphics2D graphics = canvas.createGraphics();
graphics.drawImage(leftImage, 0, 0, null);
graphics.drawImage(rightImage, leftImage.getWidth() + gap, 0, null);
graphics.dispose();

String multiImagePath = ExampleAssist.pathCombine(FOLDER, fileName);
ImageIO.write(canvas, "PNG", java.nio.file.Paths.get(multiImagePath).toFile());

BarCodeReader barCodeReader =
        new BarCodeReader(multiImagePath, DecodeType.ALL_SUPPORTED_TYPES);
ExampleAssist.assertRecognized(barCodeReader, fileName, 2, DecodeType.CODE_128, DecodeType.QR);

BarCodeReader returns both results, and the helper assertRecognized verifies that at least one Code 128 and one QR code were found.

You can combine this pattern with the strategies from section 1:

  • restrict the image to a single type to ignore unrelated symbols (for example Code 128 only),
  • use MOST_COMMON_TYPES to get only typical formats from a mixed page,
  • use strict filtering in tests to ensure that unwanted symbologies are ignored.

6. Test fixtures and sample images

Both sample classes (ChooseRecognitionSymbology and ConfigureSymbologyTypeExample) contain helper code that generates example images used in the tests.
Images are created on demand using BarcodeGenerator and then stored under the corresponding resource folders.

For example, a Code 128 barcode fixture is created as follows:

ExampleAssist.checkOrCreateImage(FOLDER, FILE_C128, fullPath -> {
    BarcodeGenerator generator =
            new BarcodeGenerator(EncodeTypes.CODE_128, "C128-DEMO");
    generator.save(fullPath, BarCodeImageFormat.PNG);
});

The mixed QR + Code 128 image is built by generating two separate barcodes and placing them on a single canvas:

String qrTemp = Paths.get(FOLDER, "_tmp_qr.png").toString();
String c128Temp = Paths.get(FOLDER, "_tmp_c128.png").toString();

BarcodeGenerator qrGen = new BarcodeGenerator(EncodeTypes.QR, "QR-MIX");
qrGen.save(qrTemp, BarCodeImageFormat.PNG);

BarcodeGenerator c128Gen = new BarcodeGenerator(EncodeTypes.CODE_128, "C128-MIX");
c128Gen.save(c128Temp, BarCodeImageFormat.PNG);

BufferedImage qr = ImageIO.read(new File(qrTemp));
BufferedImage c128 = ImageIO.read(new File(c128Temp));

int pad = 20;
int w = qr.getWidth() + c128.getWidth() + pad * 3;
int h = Math.max(qr.getHeight(), c128.getHeight()) + pad * 2;

BufferedImage canvas = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);
Graphics2D g = canvas.createGraphics();
try {
    g.setColor(Color.WHITE);
    g.fillRect(0, 0, w, h);
    g.drawImage(qr, pad, pad, null);
    g.drawImage(c128, pad * 2 + qr.getWidth(), pad, null);
} finally {
    g.dispose();
}

ImageIO.write(canvas, "PNG", new File(outPath));

You can reuse this pattern in your own tests to create controlled multi-barcode images.

Summary

To configure symbology types effectively when using BarCodeReader in Aspose.BarCode for Java:

  • Use a single explicit DecodeType whenever you know the exact symbology (fastest and most robust).
  • Use DecodeType.MOST_COMMON_TYPES when you expect popular formats but do not want to maintain a list.
  • Use grouped types such as DecodeType.TYPES_1D and DecodeType.TYPES_2D when your application is limited to linear or 2D codes.
  • Use DecodeType.ALL_SUPPORTED_TYPES only for discovery and diagnostic purposes.
  • Pass multiple explicit types or configure a custom subset with setBarCodeReadType(...) when your application supports a small, well-defined set of symbologies.
  • Use strict filtering (for example, a deliberately wrong DecodeType) in tests to catch false positives.
  • For mixed images, combine broad or grouped types with result inspection to verify that all expected symbologies are present.
  • For 2D codes such as Data Matrix, prefer the exact DecodeType to avoid ambiguity and improve robustness.

Use the ChooseRecognitionSymbology and ConfigureSymbologyTypeExample classes as references when designing your own symbology selection and recognition strategy.

Reading Code Text Reading Metadata