ECodeReader - Unified Interface

The 3 supported codes in a single image

Purpose of ECodeReader

ECodeReader integrates the functionality of EasyBarCode, EasyMatrixCode and EasyQRCode in a single unified interface.

In a single ECodeReader::Read ^{.NET Python} operation, ECodeReader locates and decodes the 3 kinds of codes supported by eVision, namely bar codes, QR codes and data matrix codes.

For more information about these codes and the associated support, please refer to the EasyBarCode, EasyMatrixCode and EasyQRCode user guides.

Reading a Set of Codes

You can read the codes in an image automatically as follows:

• Create an ECodeReader ^{.NET Python} object.

• Call the ECodeReader::Read ^{.NET Python} method to return a vector of ECode ^{.NET Python}.

• Each instance contains, among others, the string ^{.NET Python} embedded in the code.

C++

#include <eVision/EasyID/ECodeReader.h>

using namespace eVision;

// Image constructor
EImageBW8 srcImage;

// Bar code reader constructor
ECodeReader reader;

// Set the max number of codes of each type to find
reader.SetMaxNumCodesPerType(2);

// Read the barcodes in the source image
std::vector<ECode> results = reader.Read(srcImage);

// Get decoded string
std::string decodedString = results[0].GetDecodedString();

C#

using eVision;

// Image constructor
EImageBW8 srcImage = new EImageBW8();

// Bar code reader constructor
ECodeReader reader = new ECodeReader();

// Set the max number of codes of each type to find
reader.MaxNumCodesPerType = 2;

// Read the bar codes in the source image
ECode[] results = reader.Read(srcImage);

// Get decoded string
string decodedString = results[0].DecodedString;

Python

import eVision

# Image constructor
srcImage = eVision.EImageBW8()

# Bar code reader constructor
reader = eVision.ECodeReader()

# Set the max number of codes of each type to find
reader.MaxNumCodesPerType = 2

# Read the bar codes in the source image
results = reader.Read(srcImage)

# Get decoded string
decodedString = results[0].DecodedString

Read Parameters

• By default, ECodeReader ^{.NET Python} searches for all supported types of code in the image.

  • Use the property ECodeReader::GetEnabledCodeTypes ^{.NET Python} if you want to disable (or enable) specific code types.

Warning

If one of the supported types of code is not present in the image, it is recommended to disable that type. Otherwise the corresponding reader runs and may slow the whole process.

• Use ECodeReader::SetTimeOut ^{.NET Python} to set a time-out to the ECodeReader::Read ^{.NET Python} process.

  • The time-out is set for each of the underlying code readers that run in parallel. And so it also limits the total ECodeReader::Read ^{.NET Python} processing time.

• Use the property ECodeReader::GetMaxNumCodesPerType ^{.NET Python} to set the maximum number of codes to search for each type.

• Use the following properties to set the settings specific to one of the supported types of code:

  • ECodeReader::GetBarCodeReader ^{.NET Python} retrieves the underlying EBarCodeReader ^{.NET Python} instance.

    See also

    For more information about the relevant settings, refer to the documentation of EasyBarCode.

  • ECodeReader::GetMatrixCodeReader ^{.NET Python} retrieves the underlying EMatrixCodeReader ^{.NET Python} instance.

    See also

    For more information about the relevant settings, refer to the documentation of EasyMatrixCode.

  • ECodeReader::GetQRCodeReader ^{.NET Python} retrieves the underlying EQRCodeReader ^{.NET Python} instance.

    See also

    For more information about the relevant settings, refer to the documentation of EasyQRCode.

Code Specific Results

The ECodeReader::Read ^{.NET Python} method returns a vector of ECode ^{.NET Python}, from these:

• Use the property ECode::GetDecodedString ^{.NET Python} to retrieve the contents of the code.

• Use the property ECode::GetIsGS1 ^{.NET Python} to query whether the code uses the GS1 standard.

• Use the method ECode::DrawPosition ^{.NET Python} to draw the position of the code.

• Use the property ECode::GetCodeType ^{.NET Python} if you need to know the specific type of the code.

• Use the following properties to retrieve the information specific to a given type of code from an ECode ^{.NET Python} instance:

  • ECode::GetBarCode ^{.NET Python} returns an EBarCode ^{.NET Python} object.

    See also

    For more information, refer to the documentation of EBarCode.

  • ECode::GetMatrixCode ^{.NET Python} returns a EMatrixCode ^{.NET Python} object.

    See also

    For more information, refer to the documentation of EMatrixCode.

  • ECode::GetQRCode ^{.NET Python} returns an EQRCode ^{.NET Python} object.

    See also

    For more information, refer to the documentation of EQRCode.

Multithreading

ECodeReader always parallelizes the location and the decoding of the different types of code.

• Easy::SetMaxNumberOfProcessingThreads ^{.NET Python} has no effect on this behavior.

• However, Easy::SetMaxNumberOfProcessingThreads ^{.NET Python} has the intended effect on the underlying code readers and speeds up the whole process.

Reading Using a Grid

If the codes in the images are arranged in a regular grid-like fashion:

• Use the dedicated method overloads ECodeReader::Read ^{.NET Python} that return ECodeGrid ^{.NET Python} objects to improve the reliability and the speed of the reading.

• Use the methods EGrid::SetEnableCell ^{.NET Python}, EGrid::SetEnableRow ^{.NET Python}, EGrid::SetEnableColumn ^{.NET Python} or EGrid::SetEnableAll ^{.NET Python} to disable the processing of cells that you know do not contain any code.

• Use the method ECodeGrid::GetResults ^{.NET Python} of the returned ECodeGrid ^{.NET Python} object to retrieve the codes read in each cell of the defined grid.

Reading of codes arranged in a grid

Quick Links

Code snippets

Code snippets for ECodeReader.

ECodeReader

List of Supported Codes

All the code symbologies read by the text and code reading libraries.

List of Supported Codes

Code Grading

Assess the printing quality of your bar, data matrix and QR codes.

Code Grading