Readme.markdown
1QR Code generator library - Java
2================================
3
4
5Introduction
6------------
7
8This project aims to be the best, clearest QR Code generator library. The primary goals are flexible options and absolute correctness. Secondary goals are compact implementation size and good documentation comments.
9
10Home page with live JavaScript demo, extensive descriptions, and competitor comparisons: https://www.nayuki.io/page/qr-code-generator-library
11
12
13Features
14--------
15
16Core features:
17
18* Significantly shorter code but more documentation comments compared to competing libraries
19* Supports encoding all 40 versions (sizes) and all 4 error correction levels, as per the QR Code Model 2 standard
20* Output format: Raw modules/pixels of the QR symbol
21* Detects finder-like penalty patterns more accurately than other implementations
22* Encodes numeric and special-alphanumeric text in less space than general text
23* Open-source code under the permissive MIT License
24
25Manual parameters:
26
27* User can specify minimum and maximum version numbers allowed, then library will automatically choose smallest version in the range that fits the data
28* User can specify mask pattern manually, otherwise library will automatically evaluate all 8 masks and select the optimal one
29* User can specify absolute error correction level, or allow the library to boost it if it doesn't increase the version number
30* User can create a list of data segments manually and add ECI segments
31
32Optional advanced features:
33
34* Encodes Japanese Unicode text in kanji mode to save a lot of space compared to UTF-8 bytes
35* Computes optimal segment mode switching for text with mixed numeric/alphanumeric/general/kanji parts
36
37More information about QR Code technology and this library's design can be found on the project home page.
38
39
40Examples
41--------
42
43```java
44import java.awt.image.BufferedImage;
45import java.io.File;
46import java.util.List;
47import javax.imageio.ImageIO;
48import io.nayuki.qrcodegen.*;
49
50// Simple operation
51QrCode qr0 = QrCode.encodeText("Hello, world!", QrCode.Ecc.MEDIUM);
52BufferedImage img = toImage(qr0, 4, 10); // See QrCodeGeneratorDemo
53ImageIO.write(img, "png", new File("qr-code.png"));
54
55// Manual operation
56List<QrSegment> segs = QrSegment.makeSegments("3141592653589793238462643383");
57QrCode qr1 = QrCode.encodeSegments(segs, QrCode.Ecc.HIGH, 5, 5, 2, false);
58for (int y = 0; y < qr1.size; y++) {
59 for (int x = 0; x < qr1.size; x++) {
60 (... paint qr1.getModule(x, y) ...)
61 }
62}
63```
64
65More complete set of examples: https://github.com/nayuki/QR-Code-generator/blob/master/java/QrCodeGeneratorDemo.java .
66
