EasyBarCode - Reading Bar Codes¶

Bar Code Definition¶

A bar code is a 2D pattern of parallel bars and spaces of varying thickness that represents a character string.

These bars and spaces are arranged according to a convention named symbology (see supported symbologies), that specifies the character set and the encoding rules.

Purpose of the EasyBarCode library¶

The EasyBarCode library allows to read bar codes in images:

The reading is fast and robust.
Several codes can be read in the same image.
Many symbologies are supported
The processing can be limited to an ERegion ^.NET ^Python in the image.
Specific support is provided for codes arranged in a grid.
The bar codes can be graded according to the ISO 15416 norms.

Note

Using a different set of classes, the EasyBarCode library also supports mail bar codes.

Reading Bar Codes¶

Use the method EBarCodeReader::Read ^.NET ^Python to locate the bar codes as EBarCode ^.NET ^Python objects in an image and decode them.
This method returns a vector of EBarCode ^.NET ^Python objects for each bar code in the field of view, up to the maximum set with EBarCodeReader::SetMaxNumCodes ^.NET ^Python. By default, this maximum is set to 1 to optimize the process in the prevalent single-code cases.

Warning

Be aware that setting MaxNumCodes to a value bigger than the number of codes in big images can make EasyBarCode slow, as it will keep trying to find codes that do not exist in the image.

Each instance contains, among others, the decoded string ^.NET ^Python embedded in the bar code.

Note

The relevant classes of the EasyBarCode library are stored in the namespace EasyBarCode2. Classes outside that namespace (refered to as EasyBarCode1) are an earlier version of the EasyBarCode library, now deprecated.

C++

#include <eVision/EasyBarCode/EasyBarCode2/EBarCodeReader.h>

using namespace eVision;

// Image constructor
EImageBW8 srcImage;

// Bar code reader constructor
EasyBarCode2::EBarCodeReader reader;

// Set the max number of bar codes to find
reader.SetMaxNumCodes(6);

// Read the barcodes in the source image
std::vector<EasyBarCode2::EBarCode> results = reader.Read(srcImage);

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

using eVision;

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

// Bar code reader constructor
eVision.EasyBarCode2.EBarCodeReader reader = new eVision.EasyBarCode2.EBarCodeReader();

// Set the max number of bar codes to find
reader.MaxNumCodes = 6;

// Read the bar codes in the source image
eVision.EasyBarCode2.EBarCode[] results = reader.Read(srcImage);

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

Python

import eVision
from eVision import EasyBarCode2

# Image constructor
srcImage = eVision.EImageBW8()

# Bar code reader constructor
reader = EasyBarCode2.EBarCodeReader()

# Set the max number of bar codes to find
reader.MaxNumCodes = 6

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

# Get decoded string
decodedString = results[0].GetDecodedString()

Contents¶

Using EasyBarCode

How to use the EasyBarCode library.

Using EasyBarCode

Reading mail bar codes

How to use the EasyBarCode library to read mail bar codes.

EasyMailBarCode - Reading Mail Bar Codes

Using EasyBarCode1 (deprecated)

How to use the first version of the EasyBarCode library, now deprecated.

EasyBarCode1 - Reading Bar Codes (deprecated)

Quick Links¶

Reference

List of all Classes, Structs and Enumerations of the EasyBarCode library.

EasyBarCode API Guide

Code snippets

Code snippets for the EasyBarCode library.

EasyBarCode

List of Supported Codes

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

Linear bar codes (1D)

Code Grading

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

Code Grading

ECodeReader

Read bar, data matrix and QR codes using a unified interface.

ECodeReader - Unified Interface