如何在java中乘以2個矩陣，然後將結果用作Imgproc.warp的變換矩陣查看函數

Question

我想創建3個矩陣：3x4的B代碼爲3x4，B代表4x4的B代碼，C代表4x3的C代碼。然後，我想將它們相乘D = A *（B * C）以接收3x3矩陣 然後用D調用warpPerspective。 以上所有內容都需要使用Java完成。在C++中，它非常容易反對Java，我找不到任何Java實現的實例。

Answer 1

package test; 

import org.opencv.core.Core; 
import org.opencv.core.CvType; 
import org.opencv.core.Mat; 
import org.opencv.core.Size; 
import org.opencv.imgproc.Imgproc; 

public class MatrixMul { 

    static { 
     System.loadLibrary(Core.NATIVE_LIBRARY_NAME); 
    } 

    public static void main(String[] args) { 
     Mat A = new Mat(3, 4, CvType.CV_32FC1); 
     Mat B = new Mat(4, 4, CvType.CV_32FC1); 
     Mat C = new Mat(4, 3, CvType.CV_32FC1); 
     Mat tmp = new Mat(); 
     Mat D = new Mat(); 

     A.put(0, 0, new float[] { 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3 }); 
     B.put(0, 0, new float[] { 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4 }); 
     C.put(0, 0, new float[] { 1, 2, 3, 1, 2, 3, 1, 2, 3, 1, 2, 3 }); 

     Core.gemm(B, C, 1, new Mat(), 0, tmp); 
     Core.gemm(A, tmp, 1, new Mat(), 0, D); 

//  Mat src = ... 
//  Mat dst = new Mat(); 
//  Imgproc.warpPerspective(src, dst, D, new Size(3,3)); 

     System.out.println("A =\n" + A.dump()); 
     System.out.println("B =\n" + B.dump()); 
     System.out.println("C =\n" + C.dump()); 
     System.out.println("B * C =\n" + tmp.dump()); 
     System.out.println("D = A * (B * C) =\n" + D.dump()); 
    } 

}