使用Zxing生成具有自定义点形状的QR码 [英] Generate QR codes with custom dot shapes using zxing

问题描述

我正在编写一个应用程序，以生成具有自定义点形状的QR码.使用zxing做到这一点的最佳方法是什么?

到目前为止，我已经研究了源代码，并且看到数据位写在

  public static void main(String [] args){尝试 {generateQRCodeImage("https://www.google.com"，300、300，"./MyQRCode.png")；} catch(Exception e){e.printStackTrace();}}私人静态void generateQRCodeImage(String text，int width，int height，String filePath)抛出WriterException，IOException {最终Map< EncodeHintType，Object>encodingHints = new HashMap<>();encodingHints.put(EncodeHintType.CHARACTER_SET，"UTF-8")；QRCode代码= Encoder.encode(text，ErrorCorrectionLevel.H，encodingHints);BufferedImage image = renderQRImage(code，width，height，4);尝试(FileOutputStream流=新的FileOutputStream(filePath)){stream.write(bufferedImageToBytes(image));}}私有静态BufferedImage renderQRImage(QRCode代码，int宽度，int高度，int quietZone){BufferedImage图片=新的BufferedImage(宽度，高度，BufferedImage.TYPE_INT_ARGB);Graphics2D graphics = image.createGraphics();graphics.setRenderingHint(RenderingHints.KEY_ANTIALIASING，RenderingHints.VALUE_ANTIALIAS_ON);graphics.setBackground(Color.white);graphics.clearRect(0，0，宽度，高度);graphics.setColor(Color.black);ByteMatrix输入= code.getMatrix();如果(输入==空){抛出新的IllegalStateException();}int inputWidth = input.getWidth();int inputHeight = input.getHeight();int qrWidth = inputWidth +(quietZone * 2);int qrHeight = inputHeight +(quietZone * 2);int outputWidth = Math.max(width，qrWidth);int outputHeight = Math.max(height，qrHeight);整数倍= Math.min(outputWidth/qrWidth，outputHeight/qrHeight);int leftPadding =(outputWidth-(inputWidth *倍数))/2;int topPadding =(outputHeight-(inputHeight *倍数))/2;最终int FINDER_PATTERN_SIZE = 7;最终浮动CIRCLE_SCALE_DOWN_FACTOR = 21f/30f;int circleSize =(int)(多个* CIRCLE_SCALE_DOWN_FACTOR);for(int inputY = 0，outputY = topPadding; inputY< inputHeight; inputY ++，outputY + =多个){for(int inputX = 0，outputX = leftPadding; inputX< inputWidth; inputX ++，outputX + =多个){如果(input.get(inputX，inputY)== 1){如果(！(inputX< = FINDER_PATTERN_SIZE&& inputY< = FINDER_PATTERN_SIZE ||inputX> = inputWidth-FINDER_PATTERN_SIZE&&inputY< = FINDER_PATTERN_SIZE ||inputX< = FINDER_PATTERN_SIZE&&inputY> = inputHeight-FINDER_PATTERN_SIZE)){graphics.fillOval(outputX，outputY，circleSize，circleSize);}}}}int circleDiameter =多个* FINDER_PATTERN_SIZE;drawFinderPatternCircleStyle(graphics，leftPadding，topPadding，circleDiameter);drawFinderPatternCircleStyle(graphics，leftPadding +(inputWidth-FINDER_PATTERN_SIZE)* multiple，topPadding，circleDiameter);drawFinderPatternCircleStyle(graphics，leftPadding，topPadding +(inputHeight-FINDER_PATTERN_SIZE)* multiple，circleDiameter);返回图像；}private static void drawFinderPatternCircleStyle(Graphics2D graphics，int x，int y，int circleDiameter){最终int WHITE_CIRCLE_DIAMETER = circleDiameter * 5/7;final int WHITE_CIRCLE_OFFSET = circleDiameter/7;最终int MIDDLE_DOT_DIAMETER = circleDiameter * 3/7;最终int MIDDLE_DOT_OFFSET = circleDiameter * 2/7;graphics.setColor(Color.black);graphics.fillOval(x，y，circleDiameter，circleDiameter);graphics.setColor(Color.white);graphics.fillOval(x + WHITE_CIRCLE_OFFSET，y + WHITE_CIRCLE_OFFSET，WHITE_CIRCLE_DIAMETER，WHITE_CIRCLE_DIAMETER);graphics.setColor(Color.black);graphics.fillOval(x + MIDDLE_DOT_OFFSET，y + MIDDLE_DOT_OFFSET，MIDDLE_DOT_DIAMETER，MIDDLE_DOT_DIAMETER);} 

Maven依赖项:

 < dependency>< groupId> com.google.zxing</groupId>< artifactId> core</artifactId>< version> 3.4.0</version></dependency> 

I'm writing an application to generate QR codes with custom dot shapes. What's the best way to do this using zxing?

So far, I've dug through the source code and I see that the data bits are written in com.google.zxing.qrcode.encoder.MatrixUtil.embedDataBits(). I think I could add some code on to the end of this function which would allow me to mask the dots but I'm not sure how to do this in Java. I can't extend the class because it's declared as final. Would it be a good idea and if so how would I extend this method in that way?

The other option I've been looking at involves post-processing the image produced by QRCode but this is really complex I think as I'd have to find a way to discern the dots from the positioning squares.

Is there a better way to do what I'm looking to do? Is there another QR code library besides zxing which can do what I'm looking to do out of the box?

P.S. I want to note that this is not a duplicate of this question although the keywords are similar.

解决方案

The following java code uses zxing to make a QR-code image with circular dots and a circular finder pattern (custom rendering style). This can be adapted to other custom render styles.

I use the Encoder class directly and bypass QRCodeWriter and MatrixToImageWriter to gain enough control to alter the rendering. To alter the finder pattern, I use the fact that the finder pattern is always 7 dots wide/tall. Otherwise I would have to create a custom version of MatrixUtil (and perhaps Encoder).

Example QR Code Image Generated:

    public static void main(String[] args) {
        try {
            generateQRCodeImage("https://www.google.com", 300, 300, "./MyQRCode.png");
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    private static void generateQRCodeImage(String text, int width, int height, String filePath) throws WriterException, IOException {
        final Map<EncodeHintType, Object> encodingHints = new HashMap<>();
        encodingHints.put(EncodeHintType.CHARACTER_SET, "UTF-8");
        QRCode code = Encoder.encode(text, ErrorCorrectionLevel.H, encodingHints);
        BufferedImage image = renderQRImage(code, width, height, 4);
        
        try (FileOutputStream stream = new FileOutputStream(filePath)) {
            stream.write(bufferedImageToBytes(image));
        }
    }

    private static BufferedImage renderQRImage(QRCode code, int width, int height, int quietZone) {
        BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB);
        Graphics2D graphics = image.createGraphics();

        graphics.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
        graphics.setBackground(Color.white);
        graphics.clearRect(0, 0, width, height);
        graphics.setColor(Color.black);

        ByteMatrix input = code.getMatrix();
        if (input == null) {
            throw new IllegalStateException();
        }
        int inputWidth = input.getWidth();
        int inputHeight = input.getHeight();
        int qrWidth = inputWidth + (quietZone * 2);
        int qrHeight = inputHeight + (quietZone * 2);
        int outputWidth = Math.max(width, qrWidth);
        int outputHeight = Math.max(height, qrHeight);

        int multiple = Math.min(outputWidth / qrWidth, outputHeight / qrHeight);
        int leftPadding = (outputWidth - (inputWidth * multiple)) / 2;
        int topPadding = (outputHeight - (inputHeight * multiple)) / 2;
        final int FINDER_PATTERN_SIZE = 7;
        final float CIRCLE_SCALE_DOWN_FACTOR = 21f/30f;
        int circleSize = (int) (multiple * CIRCLE_SCALE_DOWN_FACTOR);

        for (int inputY = 0, outputY = topPadding; inputY < inputHeight; inputY++, outputY += multiple) {
            for (int inputX = 0, outputX = leftPadding; inputX < inputWidth; inputX++, outputX += multiple) {
                if (input.get(inputX, inputY) == 1) {
                    if (!(inputX <= FINDER_PATTERN_SIZE && inputY <= FINDER_PATTERN_SIZE ||
                          inputX >= inputWidth - FINDER_PATTERN_SIZE && inputY <= FINDER_PATTERN_SIZE ||
                          inputX <= FINDER_PATTERN_SIZE && inputY >= inputHeight - FINDER_PATTERN_SIZE)) {
                        graphics.fillOval(outputX, outputY, circleSize, circleSize);
                    }
                }
            }
        }

        int circleDiameter = multiple * FINDER_PATTERN_SIZE;
        drawFinderPatternCircleStyle(graphics, leftPadding, topPadding, circleDiameter);
        drawFinderPatternCircleStyle(graphics, leftPadding + (inputWidth - FINDER_PATTERN_SIZE) * multiple, topPadding, circleDiameter);
        drawFinderPatternCircleStyle(graphics, leftPadding, topPadding + (inputHeight - FINDER_PATTERN_SIZE) * multiple, circleDiameter);

        return image;
    }

    private static void drawFinderPatternCircleStyle(Graphics2D graphics, int x, int y, int circleDiameter) {
        final int WHITE_CIRCLE_DIAMETER = circleDiameter*5/7;
        final int WHITE_CIRCLE_OFFSET = circleDiameter/7;
        final int MIDDLE_DOT_DIAMETER = circleDiameter*3/7;
        final int MIDDLE_DOT_OFFSET = circleDiameter*2/7;

        graphics.setColor(Color.black);
        graphics.fillOval(x, y, circleDiameter, circleDiameter);
        graphics.setColor(Color.white);
        graphics.fillOval(x + WHITE_CIRCLE_OFFSET, y + WHITE_CIRCLE_OFFSET, WHITE_CIRCLE_DIAMETER, WHITE_CIRCLE_DIAMETER);
        graphics.setColor(Color.black);
        graphics.fillOval(x + MIDDLE_DOT_OFFSET, y + MIDDLE_DOT_OFFSET, MIDDLE_DOT_DIAMETER, MIDDLE_DOT_DIAMETER);
    }

Maven dependency:

    <dependency>
        <groupId>com.google.zxing</groupId>
        <artifactId>core</artifactId>
        <version>3.4.0</version>
    </dependency>

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