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1QR Code generator library
2=========================
3
4
5Introduction
6------------
7
8This project aims to be the best, clearest QR Code generator library in multiple languages. 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](https://www.nayuki.io/page/qr-code-generator-library)
11
12
13Features
14--------
15
16Core features:
17
18* Available in 6 programming languages, all with nearly equal functionality: Java, TypeScript/JavaScript, Python, Rust, C++, C
19* Significantly shorter code but more documentation comments compared to competing libraries
20* Supports encoding all 40 versions (sizes) and all 4 error correction levels, as per the QR Code Model 2 standard
21* Output formats: Raw modules/pixels of the QR symbol (all languages), SVG XML string (all languages except C), `BufferedImage` raster bitmap (Java only), HTML5 canvas (TypeScript/JavaScript only)
22* Detects finder-like penalty patterns more accurately than other implementations
23* Encodes numeric and special-alphanumeric text in less space than general text
24* Open source code under the permissive MIT License
25
26Manual parameters:
27
28* User can specify minimum and maximum version numbers allowed, then library will automatically choose smallest version in the range that fits the data
29* User can specify mask pattern manually, otherwise library will automatically evaluate all 8 masks and select the optimal one
30* User can specify absolute error correction level, or allow the library to boost it if it doesn't increase the version number
31* User can create a list of data segments manually and add ECI segments
32
33Optional advanced features (Java only):
34
35* Encodes Japanese Unicode text in kanji mode to save a lot of space compared to UTF-8 bytes
36* Computes optimal segment mode switching for text with mixed numeric/alphanumeric/general/kanji parts
37
38More information about QR Code technology and this library's design can be found on the project home page.
39
40
41Examples
42--------
43
44Java language:
45
46    import java.awt.image.BufferedImage;
47    import java.io.File;
48    import java.util.List;
49    import javax.imageio.ImageIO;
50    import io.nayuki.qrcodegen.*;
51
52    // Simple operation
53    QrCode qr0 = QrCode.encodeText("Hello, world!", QrCode.Ecc.MEDIUM);
54    BufferedImage img = qr0.toImage(4, 10);
55    ImageIO.write(img, "png", new File("qr-code.png"));
56
57    // Manual operation
58    List<QrSegment> segs = QrSegment.makeSegments("3141592653589793238462643383");
59    QrCode qr1 = QrCode.encodeSegments(segs, QrCode.Ecc.HIGH, 5, 5, 2, false);
60    for (int y = 0; y < qr1.size; y++) {
61        for (int x = 0; x < qr1.size; x++) {
62            (... paint qr1.getModule(x, y) ...)
63        }
64    }
65
66TypeScript/JavaScript languages:
67
68    // Name abbreviated for the sake of these examples here
69    var QRC = qrcodegen.QrCode;
70
71    // Simple operation
72    var qr0 = QRC.encodeText("Hello, world!", QRC.Ecc.MEDIUM);
73    var svg = qr0.toSvgString(4);
74
75    // Manual operation
76    var segs = qrcodegen.QrSegment.makeSegments("3141592653589793238462643383");
77    var qr1 = QRC.encodeSegments(segs, QRC.Ecc.HIGH, 5, 5, 2, false);
78    for (var y = 0; y < qr1.size; y++) {
79        for (var x = 0; x < qr1.size; x++) {
80            (... paint qr1.getModule(x, y) ...)
81        }
82    }
83
84Python language:
85
86    from qrcodegen import *
87
88    # Simple operation
89    qr0 = QrCode.encode_text("Hello, world!", QrCode.Ecc.MEDIUM)
90    svg = qr0.to_svg_str(4)
91
92    # Manual operation
93    segs = QrSegment.make_segments("3141592653589793238462643383")
94    qr1 = QrCode.encode_segments(segs, QrCode.Ecc.HIGH, 5, 5, 2, False)
95    for y in range(qr1.get_size()):
96        for x in range(qr1.get_size()):
97            (... paint qr1.get_module(x, y) ...)
98
99C++ language:
100
101    #include <string>
102    #include <vector>
103    #include "QrCode.hpp"
104    using namespace qrcodegen;
105
106    // Simple operation
107    QrCode qr0 = QrCode::encodeText("Hello, world!", QrCode::Ecc::MEDIUM);
108    std::string svg = qr0.toSvgString(4);
109
110    // Manual operation
111    std::vector<QrSegment> segs =
112        QrSegment::makeSegments("3141592653589793238462643383");
113    QrCode qr1 = QrCode::encodeSegments(
114        segs, QrCode::Ecc::HIGH, 5, 5, 2, false);
115    for (int y = 0; y < qr1.getSize(); y++) {
116        for (int x = 0; x < qr1.getSize(); x++) {
117            (... paint qr1.getModule(x, y) ...)
118        }
119    }
120
121C language:
122
123    #include <stdbool.h>
124    #include <stdint.h>
125    #include "qrcodegen.h"
126
127    // Text data
128    uint8_t qr0[qrcodegen_BUFFER_LEN_MAX];
129    uint8_t tempBuffer[qrcodegen_BUFFER_LEN_MAX];
130    bool ok = qrcodegen_encodeText("Hello, world!",
131        tempBuffer, qr0, qrcodegen_Ecc_MEDIUM,
132        qrcodegen_VERSION_MIN, qrcodegen_VERSION_MAX,
133        qrcodegen_Mask_AUTO, true);
134    if (!ok)
135        return;
136
137    int size = qrcodegen_getSize(qr0);
138    for (int y = 0; y < size; y++) {
139        for (int x = 0; x < size; x++) {
140            (... paint qrcodegen_getModule(qr0, x, y) ...)
141        }
142    }
143
144    // Binary data
145    uint8_t dataAndTemp[qrcodegen_BUFFER_LEN_FOR_VERSION(7)]
146        = {0xE3, 0x81, 0x82};
147    uint8_t qr1[qrcodegen_BUFFER_LEN_FOR_VERSION(7)];
148    ok = qrcodegen_encodeBinary(dataAndTemp, 3, qr1,
149        qrcodegen_Ecc_HIGH, 2, 7, qrcodegen_Mask_4, false);
150
151Rust language:
152
153    extern crate qrcodegen;
154    use qrcodegen::QrCode;
155    use qrcodegen::QrCodeEcc;
156    use qrcodegen::QrSegment;
157
158    // Simple operation
159    let qr = QrCode::encode_text("Hello, world!",
160        QrCodeEcc::Medium).unwrap();
161    let svg = qr.to_svg_string(4);
162
163    // Manual operation
164    let chrs: Vec<char> = "3141592653589793238462643383".chars().collect();
165    let segs = QrSegment::make_segments(&chrs);
166    let qr = QrCode::encode_segments_advanced(
167        &segs, QrCodeEcc::High, 5, 5, Some(Mask::new(2)), false).unwrap();
168    for y in 0 .. qr.size() {
169        for x in 0 .. qr.size() {
170            (... paint qr.get_module(x, y) ...)
171        }
172    }
173
174
175License
176-------
177
178Copyright © 2020 Project Nayuki. (MIT License)
179[https://www.nayuki.io/page/qr-code-generator-library](https://www.nayuki.io/page/qr-code-generator-library)
180
181Permission is hereby granted, free of charge, to any person obtaining a copy of
182this software and associated documentation files (the "Software"), to deal in
183the Software without restriction, including without limitation the rights to
184use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
185the Software, and to permit persons to whom the Software is furnished to do so,
186subject to the following conditions:
187
188* The above copyright notice and this permission notice shall be included in
189  all copies or substantial portions of the Software.
190
191* The Software is provided "as is", without warranty of any kind, express or
192  implied, including but not limited to the warranties of merchantability,
193  fitness for a particular purpose and noninfringement. In no event shall the
194  authors or copyright holders be liable for any claim, damages or other
195  liability, whether in an action of contract, tort or otherwise, arising from,
196  out of or in connection with the Software or the use or other dealings in the
197  Software.
198