Question

如何读取/写入CvMat（Java）数组？在下面的代码中，我将CvMat放入数组中。但阅读似乎没有得到CvMat。

import com.googlecode.javacpp.Pointer;
import com.googlecode.javacv.cpp.opencv_core;
import static com.googlecode.javacv.cpp.opencv_core.CV_IS_MAT;
import com.googlecode.javacv.cpp.opencv_core.CvMat;
import static com.googlecode.javacv.cpp.opencv_core.IPL_DEPTH_32F;
import com.googlecode.javacv.cpp.opencv_core.IplImage;
import static com.googlecode.javacv.cpp.opencv_core.cvSize;

public class Ask {

    public static void main(String[] args) {
        new Ask().go();
    }

    private void go() {
        CvMat matQ = new opencv_core.CvMat(3); //array of 3 CvMat
        IplImage i = opencv_core.cvCreateImage(cvSize(10, 10), IPL_DEPTH_32F, 3); //just to have an image

        CvMat x = i.asCvMat(); //a CvMat of the image
        System.out.println(CV_IS_MAT(x)); //true, it's a mat

        matQ.position(0).put(x); //store it to array at position 0

        System.out.println(CV_IS_MAT(matQ.position(0))); //false!
        System.out.println(CV_IS_MAT(matQ)); //also false
    }
}

Answer 1

如果您有cvMat，例如，如果您阅读了图像路径：

String imgPath =“./ src / Imgs / chessboard.png”;
Mat imgSrc = Highgui.imread（imgPath）;

或者如果你创建了cvMat元素：

Mat imgSrc2 = Mat.eye（3,3，CvType.CV_8UC1）;

你可以把它转换为java元素IplImage，BufferedImage *：

BufferedImage img;
img = imgIO.Mat2BufferedImage(imgSrc);

使用以下命令在控制台中显示cvmat的内容：

System.out.println（“cvMat element：\ n”+ imgSrc.dump（））;

如果您只想将一个元素修改为矩阵：

imgSrc.put(row, col, value);
imgSrc.put(2, 2, 1);

*函数Mat2BufferedImage：

// source: http://answers.opencv.org/question/10344/opencv-java-load-image-to-gui/

    /**
 * @param 
 * @return The output can be assigned either to BufferedImage or to Image
 */
public BufferedImage Mat2BufferedImage(Mat m){

    int type = BufferedImage.TYPE_BYTE_GRAY;
    if ( m.channels() > 1 ) {
        type = BufferedImage.TYPE_3BYTE_BGR;
    }
    int bufferSize = m.channels()*m.cols()*m.rows();
    byte [] b = new byte[bufferSize];
    m.get(0,0,b); // get all the pixels
    BufferedImage image = new BufferedImage(m.cols(),m.rows(), type);
    final byte[] targetPixels = ((DataBufferByte) image.getRaster().getDataBuffer()).getData();
    System.arraycopy(b, 0, targetPixels, 0, b.length);  
    return image;

}

Answer 2

如果您使用Javacv（https://github.com/bytedeco/javacv），这是一项非常简单的任务。

 String img ="Image.jpg";
 IplImage newImage0 = cvLoadImage(img);
 //import static org.bytedeco.javacpp.opencv_core.IplImage;

或

  Mat newImage1 = imread(img);
  //import org.bytedeco.javacpp.opencv_core.Mat;
  //import static org.bytedeco.javacpp.opencv_highgui.*;

如果将其转换为CvMat类型

CvMat imgcvMat0 = newImage0.asCvMat();
CvMat imgcvMat1 = new CvMat(newImage1);
//import org.bytedeco.javacpp.opencv_core.Mat;

与将其转换回IplImage

相同

imgcvMat0.asIplImage();
or 
imgcvMat0.asBuffer();

OpenCV /如何在java中处理CvMat数组

2 个答案: