Simple matrix multiplication for Mat in iOS/Android

modules/core/misc/java/src/java/core+Mat.java

@@ -466,16 +466,32 @@ public class Mat {
     // C++: Mat Mat::mul(Mat m, double scale = 1)
     //
 
-    // javadoc: Mat::mul(m, scale)
+    /**
+     * Element-wise multiplication with scale factor
+     * @param m operand with with which to perform element-wise multiplication
+     * @param scale scale factor
+     */
     public Mat mul(Mat m, double scale) {
         return new Mat(n_mul(nativeObj, m.nativeObj, scale));
     }
 
-    // javadoc: Mat::mul(m)
+    /**
+    * Element-wise multiplication
+    * @param m operand with with which to perform element-wise multiplication
+    */
     public Mat mul(Mat m) {
         return new Mat(n_mul(nativeObj, m.nativeObj));
     }
 
+    /**
+    * Matrix multiplication
+    * @param m operand with with which to perform matrix multiplication
+    * @see Core#gemm(Mat, Mat, double, Mat, double, Mat, int)
+    */
+    public Mat matMul(Mat m) {
+        return new Mat(n_matMul(nativeObj, m.nativeObj));
+    }
+
     //
     // C++: static Mat Mat::ones(int rows, int cols, int type)
     //
@@ -1732,6 +1748,8 @@ public class Mat {
 
     private static native long n_mul(long nativeObj, long m_nativeObj);
 
+    private static native long n_matMul(long nativeObj, long m_nativeObj);
+
     // C++: static Mat Mat::ones(int rows, int cols, int type)
     private static native long n_ones(int rows, int cols, int type);
 

modules/core/misc/java/src/java/core+MatMatMul.kt

@@ -0,0 +1,3 @@
+package org.opencv.core
+
+operator fun Mat.times(other: Mat): Mat = this.matMul(other)

modules/core/misc/java/test/MatTest.java

@@ -686,6 +686,16 @@ public class MatTest extends OpenCVTestCase {
         assertMatEqual(truth, dst, EPS);
     }
 
+    public void testMatMulMat() {
+        Mat m1 = new Mat(2, 2, CvType.CV_32F, new Scalar(2));
+        Mat m2 = new Mat(2, 2, CvType.CV_32F, new Scalar(3));
+
+        dst = m1.matMul(m2);
+
+        truth = new Mat(2, 2, CvType.CV_32F, new Scalar(12));
+        assertMatEqual(truth, dst, EPS);
+    }
+
     public void testOnesIntIntInt() {
         dst = Mat.ones(matSize, matSize, CvType.CV_32F);