For example, toImage(scale=10, border=4) means to pad the QR Code with 4 light - * border modules on all four sides, and use 10×10 pixels to represent each module. - * The resulting image only contains the hex colors 000000 and FFFFFF. - * @param scale the side length (measured in pixels, must be positive) of each module - * @param border the number of border modules to add, which must be non-negative - * @return a new image representing this QR Code, with padding and scaling - * @throws IllegalArgumentException if the scale or border is out of range, or if - * {scale, border, size} cause the image dimensions to exceed Integer.MAX_VALUE - */ - public BufferedImage toImage(int scale, int border) { - if (scale <= 0 || border < 0) - throw new IllegalArgumentException("Value out of range"); - if (border > Integer.MAX_VALUE / 2 || size + border * 2L > Integer.MAX_VALUE / scale) - throw new IllegalArgumentException("Scale or border too large"); - - BufferedImage result = new BufferedImage((size + border * 2) * scale, (size + border * 2) * scale, BufferedImage.TYPE_INT_RGB); - for (int y = 0; y < result.getHeight(); y++) { - for (int x = 0; x < result.getWidth(); x++) { - boolean color = getModule(x / scale - border, y / scale - border); - result.setRGB(x, y, color ? 0x000000 : 0xFFFFFF); - } - } - return result; - } - - /** * Returns a string of SVG code for an image depicting this QR Code, with the specified number * of border modules. The string always uses Unix newlines (\n), regardless of the platform. diff --git a/src/io/nayuki/fastqrcodegen/QrCodeGeneratorDemo.java b/src/io/nayuki/fastqrcodegen/QrCodeGeneratorDemo.java index f57836c..792b42d 100644 --- a/src/io/nayuki/fastqrcodegen/QrCodeGeneratorDemo.java +++ b/src/io/nayuki/fastqrcodegen/QrCodeGeneratorDemo.java @@ -33,6 +33,7 @@ import java.nio.charset.StandardCharsets; import java.nio.file.Files; import java.util.Arrays; import java.util.List; +import java.util.Objects; import javax.imageio.ImageIO; @@ -57,7 +58,7 @@ public final class QrCodeGeneratorDemo { QrCode qr = QrCode.encodeText(text, errCorLvl); // Make the QR Code symbol - BufferedImage img = qr.toImage(10, 4); // Convert to bitmap image + BufferedImage img = toImage(qr, 10, 4); // Convert to bitmap image File imgFile = new File("hello-world-QR.png"); // File path for output ImageIO.write(img, "png", imgFile); // Write image to file @@ -74,15 +75,15 @@ public final class QrCodeGeneratorDemo { // Numeric mode encoding (3.33 bits per digit) qr = QrCode.encodeText("314159265358979323846264338327950288419716939937510", QrCode.Ecc.MEDIUM); - writePng(qr.toImage(13, 1), "pi-digits-QR.png"); + writePng(toImage(qr, 13, 1), "pi-digits-QR.png"); // Alphanumeric mode encoding (5.5 bits per character) qr = QrCode.encodeText("DOLLAR-AMOUNT:$39.87 PERCENTAGE:100.00% OPERATIONS:+-*/", QrCode.Ecc.HIGH); - writePng(qr.toImage(10, 2), "alphanumeric-QR.png"); + writePng(toImage(qr, 10, 2), "alphanumeric-QR.png"); // Unicode text as UTF-8 qr = QrCode.encodeText("こんにちwa、世界！ αβγδ", QrCode.Ecc.QUARTILE); - writePng(qr.toImage(10, 3), "unicode-QR.png"); + writePng(toImage(qr, 10, 3), "unicode-QR.png"); // Moderately large QR Code using longer text (from Lewis Carroll's Alice in Wonderland) qr = QrCode.encodeText( @@ -93,7 +94,7 @@ public final class QrCodeGeneratorDemo { + "for the hot day made her feel very sleepy and stupid), whether the pleasure of making a " + "daisy-chain would be worth the trouble of getting up and picking the daisies, when suddenly " + "a White Rabbit with pink eyes ran close by her.", QrCode.Ecc.HIGH); - writePng(qr.toImage(6, 10), "alice-wonderland-QR.png"); + writePng(toImage(qr, 6, 10), "alice-wonderland-QR.png"); } @@ -106,32 +107,32 @@ public final class QrCodeGeneratorDemo { String silver0 = "THE SQUARE ROOT OF 2 IS 1."; String silver1 = "41421356237309504880168872420969807856967187537694807317667973799"; qr = QrCode.encodeText(silver0 + silver1, QrCode.Ecc.LOW); - writePng(qr.toImage(10, 3), "sqrt2-monolithic-QR.png"); + writePng(toImage(qr, 10, 3), "sqrt2-monolithic-QR.png"); segs = Arrays.asList( QrSegment.makeAlphanumeric(silver0), QrSegment.makeNumeric(silver1)); qr = QrCode.encodeSegments(segs, QrCode.Ecc.LOW); - writePng(qr.toImage(10, 3), "sqrt2-segmented-QR.png"); + writePng(toImage(qr, 10, 3), "sqrt2-segmented-QR.png"); // Illustration "golden" String golden0 = "Golden ratio φ = 1."; String golden1 = "6180339887498948482045868343656381177203091798057628621354486227052604628189024497072072041893911374"; String golden2 = "......"; qr = QrCode.encodeText(golden0 + golden1 + golden2, QrCode.Ecc.LOW); - writePng(qr.toImage(8, 5), "phi-monolithic-QR.png"); + writePng(toImage(qr, 8, 5), "phi-monolithic-QR.png"); segs = Arrays.asList( QrSegment.makeBytes(golden0.getBytes(StandardCharsets.UTF_8)), QrSegment.makeNumeric(golden1), QrSegment.makeAlphanumeric(golden2)); qr = QrCode.encodeSegments(segs, QrCode.Ecc.LOW); - writePng(qr.toImage(8, 5), "phi-segmented-QR.png"); + writePng(toImage(qr, 8, 5), "phi-segmented-QR.png"); // Illustration "Madoka": kanji, kana, Cyrillic, full-width Latin, Greek characters String madoka = "「魔法少女まどか☆マギカ」って、 ИАИ ｄｅｓｕ κα？"; qr = QrCode.encodeText(madoka, QrCode.Ecc.LOW); - writePng(qr.toImage(9, 4), "madoka-utf8-QR.png"); + writePng(toImage(qr, 9, 4), "madoka-utf8-QR.png"); int[] kanjiChars = { // Kanji mode encoding (13 bits per character) 0x0035, 0x1002, 0x0FC0, 0x0AED, 0x0AD7, @@ -146,7 +147,7 @@ public final class QrCodeGeneratorDemo { bb.appendBits(c, 13); segs = Arrays.asList(new QrSegment(QrSegment.Mode.KANJI, kanjiChars.length, bb.data, bb.bitLength)); qr = QrCode.encodeSegments(segs, QrCode.Ecc.LOW); - writePng(qr.toImage(9, 4), "madoka-kanji-QR.png"); + writePng(toImage(qr, 9, 4), "madoka-kanji-QR.png"); } @@ -158,26 +159,57 @@ public final class QrCodeGeneratorDemo { // Project Nayuki URL segs = QrSegment.makeSegments("https://www.nayuki.io/"); qr = QrCode.encodeSegments(segs, QrCode.Ecc.HIGH, QrCode.MIN_VERSION, QrCode.MAX_VERSION, -1, true); // Automatic mask - writePng(qr.toImage(8, 6), "project-nayuki-automask-QR.png"); + writePng(toImage(qr, 8, 6), "project-nayuki-automask-QR.png"); qr = QrCode.encodeSegments(segs, QrCode.Ecc.HIGH, QrCode.MIN_VERSION, QrCode.MAX_VERSION, 3, true); // Force mask 3 - writePng(qr.toImage(8, 6), "project-nayuki-mask3-QR.png"); + writePng(toImage(qr, 8, 6), "project-nayuki-mask3-QR.png"); // Chinese text as UTF-8 segs = QrSegment.makeSegments("維基百科（Wikipedia，聆聽i/ˌwɪkᵻˈpiːdi.ə/）是一個自由內容、公開編輯且多語言的網路百科全書協作計畫"); qr = QrCode.encodeSegments(segs, QrCode.Ecc.MEDIUM, QrCode.MIN_VERSION, QrCode.MAX_VERSION, 0, true); // Force mask 0 - writePng(qr.toImage(10, 3), "unicode-mask0-QR.png"); + writePng(toImage(qr, 10, 3), "unicode-mask0-QR.png"); qr = QrCode.encodeSegments(segs, QrCode.Ecc.MEDIUM, QrCode.MIN_VERSION, QrCode.MAX_VERSION, 1, true); // Force mask 1 - writePng(qr.toImage(10, 3), "unicode-mask1-QR.png"); + writePng(toImage(qr, 10, 3), "unicode-mask1-QR.png"); qr = QrCode.encodeSegments(segs, QrCode.Ecc.MEDIUM, QrCode.MIN_VERSION, QrCode.MAX_VERSION, 5, true); // Force mask 5 - writePng(qr.toImage(10, 3), "unicode-mask5-QR.png"); + writePng(toImage(qr, 10, 3), "unicode-mask5-QR.png"); qr = QrCode.encodeSegments(segs, QrCode.Ecc.MEDIUM, QrCode.MIN_VERSION, QrCode.MAX_VERSION, 7, true); // Force mask 7 - writePng(qr.toImage(10, 3), "unicode-mask7-QR.png"); + writePng(toImage(qr, 10, 3), "unicode-mask7-QR.png"); } /*---- Utilities ----*/ + /** + * Returns a raster image depicting the specified QR Code, with the specified module scale and border modules. + *
For example, toImage(qr, scale=10, border=4) means to pad the QR Code with 4 light + * border modules on all four sides, and use 10×10 pixels to represent each module. + * The resulting image only contains the hex colors 000000 and FFFFFF. + * @param qr the QR Code to render (not {@code null}) + * @param scale the side length (measured in pixels, must be positive) of each module + * @param border the number of border modules to add, which must be non-negative + * @return a new image representing the QR Code, with padding and scaling + * @throws NullPointerException if the QR Code is {@code null} + * @throws IllegalArgumentException if the scale or border is out of range, or if + * {scale, border, size} cause the image dimensions to exceed Integer.MAX_VALUE + */ + private static BufferedImage toImage(QrCode qr, int scale, int border) { + Objects.requireNonNull(qr); + if (scale <= 0 || border < 0) + throw new IllegalArgumentException("Value out of range"); + if (border > Integer.MAX_VALUE / 2 || qr.size + border * 2L > Integer.MAX_VALUE / scale) + throw new IllegalArgumentException("Scale or border too large"); + + BufferedImage result = new BufferedImage((qr.size + border * 2) * scale, (qr.size + border * 2) * scale, BufferedImage.TYPE_INT_RGB); + for (int y = 0; y < result.getHeight(); y++) { + for (int x = 0; x < result.getWidth(); x++) { + boolean color = qr.getModule(x / scale - border, y / scale - border); + result.setRGB(x, y, color ? 0x000000 : 0xFFFFFF); + } + } + return result; + } + + // Helper function to reduce code duplication. private static void writePng(BufferedImage img, String filepath) throws IOException { ImageIO.write(img, "png", new File(filepath)); diff --git a/src/io/nayuki/fastqrcodegen/package-info.java b/src/io/nayuki/fastqrcodegen/package-info.java index 50ddb0f..220b8b2 100644 --- a/src/io/nayuki/fastqrcodegen/package-info.java +++ b/src/io/nayuki/fastqrcodegen/package-info.java @@ -9,7 +9,7 @@ *
Core features:
*Supports encoding all 40 versions (sizes) and all 4 error correction levels, as per the QR Code Model 2 standard
Output formats: Raw modules/pixels of the QR symbol, SVG XML string, {@code BufferedImage} raster bitmap
Output formats: Raw modules/pixels of the QR symbol, SVG XML string
Encodes numeric and special-alphanumeric text in less space than general text
Encodes Japanese Unicode text in kanji mode to save a lot of space compared to UTF-8 bytes
Computes optimal segment mode switching for text with mixed numeric/alphanumeric/general/kanji parts
Manual operation:
*import java.util.List;