Introduction to ZXing, an open-source tool for bar code/QR code

 

Following the previous introduction of a Japanese Open-Source Software (this software can only implement QRCode) Original article: Java implements code and decoding of the QR code QRCode. Now we find another excellent open-source tool-ZXing, it is more flexible and convenient, and supports multiple encoding formats.

 

Full text directory:

Basic Introduction

Demonstration of encoding and decoding of two-dimensional codes (such as QRCode)

Code (for example: EAN-13) encoding and decoding demo

[1]. Basic Introduction:

1-1. ZXing is an open source Java class library used to parse barcode and QR code in multiple formats.

Official Website: http://code.google.com/p/zxing/

Up to now, the latest version is 1.7, which supports the following encoding formats:

UPC-A and UPC-E

EAN-8 and EAN-13

Code 39

Code 93

Code 128

QR Code

ITF

Codabar

RSS-14 (all variants)

Data Matrix

PDF 417 ('alpha' quality)

Aztec ('alpha' quality)

At the same time, the official website provides Android, cpp, C #, iPhone, j2se, j2se, jruby, objc, rim, symbian and other application class libraries. For details, refer to the downloaded source code package.

 

1-2. this article, like the previous article, is mainly an example of coding and decoding of bar code (EAN-13) and QR code (QRCode) on PC, for your reference, the source code of core and javase in the source code is used. The attachment provides the compiled lib package:

Zxing. jar

Zxing-j2se.jar

For applications related to various mobile phone systems, if you are interested, you can download the official source code package, which contains detailed application descriptions.

[2] demonstration of encoding and decoding of the QR code (QRCode:

 

2-1. Encoding example:

Java code

Package michael. zxing;

 

Import java. io. File;

Import java. util. Hashtable;

 

Import com. google. zxing. BarcodeFormat;

Import com. google. zxing. EncodeHintType;

Import com. google. zxing. MultiFormatWriter;

Import com. google. zxing. client. j2se. MatrixToImageWriter;

Import com. google. zxing. common. BitMatrix;

Import com. google. zxing. qrcode. decoder. ErrorCorrectionLevel;

 

/**

* @ Blog http://sjsky.iteye.com

* @ Author Michael

*/

Public class ZxingEncoderHandler {

 

/**

* Encoding

* @ Param contents

* @ Param width

* @ Param height

* @ Param imgPath

*/

Public void encode (String contents, int width, int height, String imgPath ){

Hashtable <Object, Object> hints = new Hashtable <Object, Object> ();

// Specify the error correction level

Hints. put (EncodeHintType. ERROR_CORRECTION, ErrorCorrectionLevel. L );

// Specify the encoding format

Hints. put (EncodeHintType. CHARACTER_SET, "GBK ");

Try {

BitMatrix bitMatrix = new MultiFormatWriter (). encode (contents,

BarcodeFormat. QR_CODE, width, height, hints );

 

MatrixToImageWriter

. WriteToFile (bitMatrix, "png", new File (imgPath ));

 

} Catch (Exception e ){

E. printStackTrace ();

}

}

 

/**

* @ Param args

*/

Public static void main (String [] args ){

String imgPath = "d:/test/twocode/michael_zxing.png ";

String contents = "Hello Michael (large), welcome to Zxing! "

+ "\ NMichael's blogs [http://sjsky.iteye.com]"

+ "\ NEMail [sjsky007@gmail.com]" + "\ nTwitter [@ suncto]";

Int width = 300, height = 300;

ZxingEncoderHandler handler = new ZxingEncoderHandler ();

Handler. encode (contents, width, height, imgPath );

 

System. out. println ("Michael, you have finished zxing encode .");

}

}

The QR code generated after running is shown as follows:

 

Like in the previous article, I used the QR code scanning software of my mobile phone (I used the android quick Bi QR code) to test the recognition success as follows:

 

 

2-2. decoding example:

Java code

Package michael. zxing;

 

Import java. awt. image. BufferedImage;

Import java. io. File;

Import java. util. Hashtable;

 

Import javax. imageio. ImageIO;

 

Import com. google. zxing. BinaryBitmap;

Import com. google. zxing. DecodeHintType;

Import com. google. zxing. LuminanceSource;

Import com. google. zxing. MultiFormatReader;

Import com. google. zxing. Result;

Import com. google. zxing. client. j2se. BufferedImageLuminanceSource;

Import com. google. zxing. common. HybridBinarizer;

 

/**

* @ Blog http://sjsky.iteye.com

* @ Author Michael

*/

Public class ZxingDecoderHandler {

 

/**

* @ Param imgPath

* @ Return String

*/

Public String decode (String imgPath ){

BufferedImage image = null;

Result result = null;

Try {

Image = ImageIO. read (new File (imgPath ));

If (image = null ){

System. out. println ("the decode image may not exit .");

}

LuminanceSource source = new BufferedImageLuminanceSource (image );

BinaryBitmap bitmap = new BinaryBitmap (new HybridBinarizer (source ));

 

Hashtable <Object, Object> hints = new Hashtable <Object, Object> ();

Hints. put (DecodeHintType. CHARACTER_SET, "GBK ");

 

Result = new MultiFormatReader (). decode (bitmap, hints );

Return result. getText ();

} Catch (Exception e ){

E. printStackTrace ();

}

Return null;

}

 

/**

* @ Param args

*/

Public static void main (String [] args ){

String imgPath = "d:/test/twocode/michael_zxing.png ";

ZxingDecoderHandler handler = new ZxingDecoderHandler ();

String decodeContent = handler. decode (imgPath );

System. out. println ("the decoded content is as follows :");

System. out. println (decodeContent );

System. out. println ("Michael, you have finished zxing decode .");

 

}

}

 

 

The running result is as follows:

 

The decoded content is as follows:

Hello Michael (BIG), welcome to Zxing!

Michael's blog [http://sjsky.iteye.com]

EMail [sjsky007@gmail.com]

Twitter [@ suncto]

Michael, you have finished zxing decode.

From the test results, we can see that the decoded content is consistent with the previously encoded content.

 

[3], bar code (EAN-13) encoding and decoding Demonstration:

 

3-1. Encoding example:

Java code

Package michael. zxing;

 

Import java. io. File;

 

Import com. google. zxing. BarcodeFormat;

Import com. google. zxing. MultiFormatWriter;

Import com. google. zxing. client. j2se. MatrixToImageWriter;

Import com. google. zxing. common. BitMatrix;

 

/**

* @ Blog http://sjsky.iteye.com

* @ Author Michael

*/

Public class ZxingEAN13EncoderHandler {

 

/**

* Encoding

* @ Param contents

* @ Param width

* @ Param height

* @ Param imgPath

*/

Public void encode (String contents, int width, int height, String imgPath ){

Int codeWidth = 3 + // start guard

(7*6) + // left bars

5 + // middle guard

(7*6) + // right bars

3; // end guard

CodeWidth = Math. max (codeWidth, width );

Try {

BitMatrix bitMatrix = new MultiFormatWriter (). encode (contents,

BarcodeFormat. EAN_13, codeWidth, height, null );

 

MatrixToImageWriter

. WriteToFile (bitMatrix, "png", new File (imgPath ));

 

} Catch (Exception e ){

E. printStackTrace ();

}

}

 

/**

* @ Param args

*/

Public static void main (String [] args ){

String imgPath = "d:/test/twocode/zxing_EAN13.png ";

// Yida sugar-free chewing gum bar code

String contents = "6923450657713 ";

 

Int width = 105, height = 50;

ZxingEAN13EncoderHandler handler = new ZxingEAN13EncoderHandler ();

Handler. encode (contents, width, height, imgPath );

 

System. out. println ("Michael, you have finished zxing EAN13 encode .");

}

}

923450 657713 corresponds to Yida sugar-free chewing gum:

 

 

The generated barcode image after running is as follows:

 

The mobile phone scanning software successfully identified the following:

 

3-2. decoding example:

Java code

Package michael. zxing;

 

Import java. awt. image. BufferedImage;

Import java. io. File;

 

Import javax. imageio. ImageIO;

 

Import com. google. zxing. BinaryBitmap;

Import com. google. zxing. LuminanceSource;

Import com. google. zxing. MultiFormatReader;

Import com. google. zxing. Result;

Import com. google. zxing. client. j2se. BufferedImageLuminanceSource;

Import com. google. zxing. common. HybridBinarizer;

 

/**

* @ Blog http://sjsky.iteye.com

* @ Author Michael

*/

Public class ZxingEAN13DecoderHandler {

 

/**

* @ Param imgPath

* @ Return String

*/

Public String decode (String imgPath ){

BufferedImage image = null;

Result result = null;

Try {

Image = ImageIO. read (new File (imgPath ));

If (image = null ){

System. out. println ("the decode image may not exit .");

}

LuminanceSource source = new BufferedImageLuminanceSource (image );

BinaryBitmap bitmap = new BinaryBitmap (new HybridBinarizer (source ));

 

Result = new MultiFormatReader (). decode (bitmap, null );

Return result. getText ();

} Catch (Exception e ){

E. printStackTrace ();

}

Return null;

}

 

/**

* @ Param args

*/

Public static void main (String [] args ){

String imgPath = "d:/test/twocode/zxing_EAN13.png ";

ZxingEAN13DecoderHandler handler = new ZxingEAN13DecoderHandler ();

String decodeContent = handler. decode (imgPath );

System. out. println ("the decoded content is as follows :");

System. out. println (decodeContent );

System. out. println ("Michael, you have finished zxing EAN-13 decode .");

 

}

}

The running result is as follows:

Write

The decoded content is as follows:

6923450657713

Michael, you have finished zxing decode.

 

From the test results, we can see that the decoded content is consistent with the previously encoded content.