Question

我正在使用OpenCV开展视频捕捉项目。我已经能够使视频捕获工作，但我想将相机滤镜更改为“常规”光谱，以便香蕉不是蓝色，是黄色的哈哈。这将是RGB光谱。我在for循环中的程序中进行了转换，但我的相机视图仍然是BRG。这是一张图片。

如何让图像视图显示“真实”颜色？这是我的代码。

Mat to Image Class

import java.awt.Color;
import java.awt.image.BufferedImage;
import org.opencv.core.Core;
import org.opencv.core.Mat;

public class Mat2Image {
    Mat mat = new Mat();
    private int argb = 0;
    Color c = new Color(argb, true);
    BufferedImage img;
    byte [] dat;

    Mat2Image(){
    }

    public Mat2Image(Mat mat) {
        getSpace(mat);
    }

    public void getSpace(Mat mat) {
        this.mat = mat;
        int w = mat.cols(), h = mat.rows();
        if (dat == null || dat.length != w * h * 3)
            dat = new byte[w * h * 3];
        if (img == null || img.getWidth() != w || img.getHeight() != h || img.getType() != BufferedImage.TYPE_3BYTE_BGR)
            img = new BufferedImage(w, h, BufferedImage.TYPE_3BYTE_BGR);

        int[] holder = new int[w * h];
        holder =  img.getData().getPixels(0, 0, w, h, (int[]) null);
        for (int i = 0; i < dat.length; i++) {

            int blueChannel = (holder[i] & 0xFF0000) >> 4;
            int greenChannel = (holder[i] & 0xFF00) >> 2;
            int redChannel = (holder[i] & 0xFF);
            int rgb = (blueChannel) & (greenChannel << 2) & (redChannel << 4);

            dat[i] = (byte) rgb;
        }
    }   

    BufferedImage getImage(Mat mat) {
        getSpace(mat);
        mat.get(0, 0, dat);
        img.getRaster().setDataElements(0, 0, mat.cols(), mat.rows(), dat);
        return img;
    }
    static {
        System.loadLibrary(Core.NATIVE_LIBRARY_NAME);
    }
}

视频捕获类

    public class VideoCap {
    static {
        System.loadLibrary(Core.NATIVE_LIBRARY_NAME);
    }
    int currFrame = 0;
    VideoCapture cap;
    Mat2Image mat2Img = new Mat2Image();

    VideoCap() {
        cap = new VideoCapture();
        cap.open(0);
    }

    BufferedImage getOneFrame() {
        currFrame++;
        //currFrame is just to stop the camera of after the running for a bit.
        if (currFrame == 20) {
            cap.read(mat2Img.mat);
            System.exit(0);
        }
        cap.read(mat2Img.mat);

        return mat2Img.getImage(mat2Img.mat);
    }
}

我的JFrame类

    public class MyFrame extends JFrame {
    private JPanel contentPane;

    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            public void run() {
                try {
                    MyFrame frame = new MyFrame();
                    frame.setVisible(true);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }

    public MyFrame() {
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setBounds(100,100,650,490);
        contentPane = new JPanel();
        contentPane.setBorder(new EmptyBorder(5,5,5,5));
        setContentPane(contentPane);
        contentPane.setLayout(null);

        new MyThread().start();
    }

    VideoCap videoCap = new VideoCap();

    public void paint(Graphics g){
        g = contentPane.getGraphics();
        g.drawImage(videoCap.getOneFrame(), 0, 0, this);
    }

    class MyThread extends Thread{
        @Override
        public void run() {
            for (;;){
                repaint();
                try { Thread.sleep(30);
                } catch (InterruptedException e) {    }
            }  
        } 
    }
}

Answer 1

你正在重新排列错误的颜色 - 你没有移动足够的位，你应该使用OR（<p> What is your name?  <input id="name-input" type="text" /> <button id="submit-name" type="button">Submit it</button> </p> <p class="greeting" id="howdy"> Howdy, <span id="name-output">student</span>! </p> <h2>Brainstorms</h2> <p class="info" id="webappidea"> Text</p>）而不是AND（|）运算符来重新组合颜色。

您的代码：

应该成为：

int blueChannel = (holder[i] & 0xFF0000) >> 4;
int greenChannel = (holder[i] & 0xFF00) >> 2;
int redChannel = (holder[i] & 0xFF);
int rgb = (blueChannel) & (greenChannel << 2) & (redChannel << 4);

修改的

此外，您似乎没有使用int blueChannel = (holder[i] & 0xFF0000) >> 16; int greenChannel = (holder[i] & 0xFF00) >> 8; int redChannel = (holder[i] & 0xFF); int rgb = (blueChannel) | (greenChannel << 8) | (redChannel << 16);作为目标图片，而是使用3字节的颜色编码。因此，您更有可能需要这样做：

int[]

但是我不清楚你是从BGR转向RGB还是从RGB转向BGR。您可能需要更改最后3个分配的顺序才能使其正确。

Answer 2

我昨天花了很多时间试图打破它，我终于开始工作了。我做的第一件事是分配新图像。这是在getSpace中完成的。然后我转换分配的图像，然后从矩阵中捕获数据，然后将数据放入图像。最后3个步骤都在getImage进行。这是我如何解决它。

public void getSpace(Mat mat) {
    this.mat = mat;
    int w = mat.cols(), h = mat.rows();
    if (dat == null || dat.length != w * h * 3)
        dat = new byte[w * h * 3];
    if (img == null || img.getWidth() != w || img.getHeight() != h || img.getType() != BufferedImage.TYPE_3BYTE_BGR)
        img = new BufferedImage(w, h, BufferedImage.TYPE_3BYTE_BGR);


}

BufferedImage getImage(Mat mat) {
    getSpace(mat);
    mat.get(0, 0, dat);

    for (int i = 0; i < dat.length; i+= 3) {
        byte redChannel = dat[i];
        byte blueChannel = dat[i+2];

        dat[i] = blueChannel;
        dat[i+2] = redChannel;

    }
    img.getRaster().setDataElements(0, 0, mat.cols(), mat.rows(), dat);
    return img;
}

Mat2Image类中的其余代码应与我在答案中未添加的代码相同，您可以尝试一下。 :)

将颜色通道从BGR转换为RGB

2 个答案: