Generate Data Matrix Barcodes in C++
Overview
Data Matrix is a 2D matrix barcode type that allows generating barcodes of rectangular and square shapes. It is a widely used industrial barcode standard that enables encoding both sets of characters and byte streams. In the maximal configuration, Data Matrix barcodes include 144 rows and columns and contain up to 1,555 bytes or 3,116 numerical (2,335 ASCII) symbols. Moreover, Data Matrix implies including additional recovery information that is used for data integrity check and error correction so that even severely damaged barcodes can be recognized. This symbology supports two main standards that are described below.
Data Matrix Standard |
Description |
|---|---|
| ECC 000-140 | A set of the outdated standards that support only square-shaped configuration, rely on obsolete encoding methods, and enable error correction based on convolutional codes. They are not recommended for use and are currently applied only to work with industrial tasks based on outdated instructions |
| ECC 200 | The actual standard that supports both square and rectangular barcodes, enables modern encoding methods, and provides Reed-Solomon error correction. It is recommended for use in all up-to-date applications |
Data Matrix Rectangular Extension
Data Matrix Rectangular Extension (DMRE) has been introduced as a part of the Data Matrix standard to enable the creation of rectangular symbols. This subtype supports all capabilities of ECC 200 and uses the Reed-Solomon error correction algorithm to detect and fix recognition errors. To generate DMRE barcodes, it is necessary to initialize the DataMatrixVersion parameter using the values from DMRE_8x48 to DMRE_26x64.
Data Matrix ECC Standard Settings
To select the required Data Matrix standard for barcode generation, Aspose.BarCode for C++ provides the DataMatrixEcc property in class DataMatrixParameters. This property can be used to set one of the following standards: ECC 000-140 (a set of the outdated standards) and ECC 200 (the new universal standard). By default, DataMatrixEcc is set to DataMatrixEccType.Ecc200.
ECC 200
To enable the ECC 200 standard explicitly, it is required to set the DataMatrixEcc property to EccAuto or Ecc200. This standard supports all data encoding modes defined in DataMatrixEncodeMode, including the possibility to work with Unicode characters using CodeTextEncoding. Recovery capacity values for error correction are strictly specified in the standard for barcodes of different sizes.
ECC 000-140
ECC 000-140 standards are supported only by the following encoding modes specified in DataMatrixEncodeMode: Auto, ASCII, and Bytes; other encoding modes in this case are automatically processed as Bytes. CodeTextEncoding, ECIEncoding, StructuredAppend, MacroCharacters, and IsReaderProgramming properties are not supported in these standards. ECC 000-140 standards have barcode layout settings that differ from those of ECC 200. Among each other, they vary only in terms of damaged data recovery percentage for different error correction levels, as outlined below.
| Error Correction Level | Damage Recovery Capacity |
|---|---|
| Ecc000 | Only error detection |
| Ecc050 | 2.8% |
| Ecc080 | 5.5% |
| Ecc100 | 12.6% |
| Ecc140 | 25% |
Encoding Mode Settings
In Aspose.BarCode for C++, developers can enable different encoding modes by initializing the DataMatrixEncodeMode property of class DataMatrixParameters. The library supports nine different encoding modes that are listed below. By default, the Auto encoding mode is set.
| Encoding Mode | Description |
|---|---|
| Auto | Similar to the ASCII encoding mode |
| ASCII | Allows encoding both ASCII symbols and byte streams, but the characters from 128 to 255 are encoded using 2 bytes. To encode an arbitrary byte stream, it is recommended to use the Full mode |
| Bytes | Encodes any character in 8 bits. This mode is the most suitable for encoding byte streams |
| C40, Text, EDIFACT, and ANSIX12 | Encode only predefined character sets using the specialized industrial encodings, such as C40, Text, EDIFACT, and ANSI X12 |
| ExtendedCodetext | Provides flexible encoding controls and the possibility to manually specify the required encoding for a part of Codetext |
If an input message to be encoded contains a Unicode character (any symbol with a value greater than 255), the entire message is processed using the encoding specified in CodeTextEncoding. This feature is valid for all encoding modes besides Custom in which the specified encoding is always enabled. The Custom mode is supported only for the ECC 200 standard.
Auto Encoding Modes
The Auto mode enables automatic switching between different encoding modes to reach the smallest possible barcode size. In this mode, the data gets processed using the encoding specified in the ECIEncoding property. By default, ISO-8859-1 is set.
ASCII Encoding Mode
The ASCII encoding mode enables both encoding ASCII symbols and byte streams; however, encoding the characters from 128 to 255 requires 2 bytes.
Bytes Mode
The Bytes mode is intended to work with byte streams; each byte is encoded using 8 bits.
Extended Encoding Controls in ExtendedCodetext
The Extended Codetext mode enables adding special control characters to the main barcode text. They serve to set extended control over data encoding and allow manually switching between different encoding schemes and ECI modes within a single barcode. To generate barcodes in this mode, it is recommended to use class DataMatrixExtCodetextBuilder.
Industrial Encoding Modes: C40, Text, EDIFACT, and ANSIX12
C40, Text, EDIFACT, and ANSIX12 encoding modes can be used to encode information using specialized industrial encodings. These modes are intended for specific industrial tasks only.
Layout Settings
Data Matrix enables different layout variants, which can be set to generate barcodes with required size parameters. To set a layout, it is necessary to initialize the DataMatrixVersion property of class DataMatrixParameters. It can take the following values:
- Auto. The barcode size will be selected automatically depending on the amount of data to be encoded.
- Values from ECC000_9x9 to ECC000_140_49x49. These options can be used to set the barcode size manually for standards ECC000-140. If the amount of input data does not fit to the selected format, an exception will be thrown.
- Values from ECC200_10x10 to ECC200_144x144, from ECC200_8x18 to ECC200_16x48, as well as from DMRE_8x48 to DMRE_26x64. These settings allow selecting the barcode size manually for standard ECC200. If the amount of input data does not fit to the selected format, an exception will be thrown.
| Layout Settings | ECC 200 Mode 12 Rows 64 Columns 64 | ECC 200 Mode 22 Rows and 22 Columns | ECC 140 Mode 29 Rows and 29 Columns |
|---|---|---|---|
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Using Macro Characters
In Aspose.BarCode for C++, developers can use so-called macro characters for Data Matrix barcode generation. Data Matrix enables abbreviating industry-specific headers and trailers in one character. This feature allows reducing the number of characters required to encode data using specific structured formats and can be enabled to address some specific industrial requirements. A macro character needs to be placed be in the first character position.
Aspect Ratio Settings
Aspect Ratio is the ratio between the width and height of a barcode. In Aspose.BarCode for C++, developers can use the AspectRatio property of class DataMatrixParameters to adjust barcode proportions according to the X and Y coordinates. This parameter is defined as a relative coefficient to the value of XDimension. In general, the Aspect Ratio value should be set to 1.
Aspect Ratio |
Is Set to 1 |
Is Set to 0.5 |
|---|---|---|
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Structured Append
Structured Append is a special mode, which allows combining together up to 16 Data Matrix symbols. To enable this mode, it is required to initialize three parameters described below:
- StructuredAppendBarcodesCount - the number of barcodes (from 2 to 16)
- StructuredAppendBarcodeId - the position of a barcode in a set (from 1 to StructuredAppendBarcodesCount)
- StructuredAppendFileId - the identifier of a file (from 1 to 64516)
Hardware Reader Initialization
To encode a special flag denoting that barcode data is intended to initialize a hardware barcode reader, it is required to set the IsReaderProgramming property.
