Add methods to reshape Mat in Java by array of shapes and retreive sizes of each dimension.

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

@@ -681,6 +681,18 @@ public class Mat {
         return retVal;
     }
 
+    //
+    // C++: Mat Mat::reshape(int cn, int newndims, const int* newsz)
+    //
+
+    // javadoc: Mat::reshape(cn, newshape)
+    public Mat reshape(int cn, int[] newshape)
+    {
+        Mat retVal = new Mat(n_reshape_1(nativeObj, cn, newshape.length, newshape));
+
+        return retVal;
+    }
+
     //
     // C++: Mat Mat::row(int y)
     //
@@ -794,6 +806,18 @@ public class Mat {
         return retVal;
     }
 
+    //
+    // C++: int Mat::size(int i)
+    //
+
+    // javadoc: Mat::size(int i)
+    public int size(int i)
+    {
+        int retVal = n_size_i(nativeObj, i);
+
+        return retVal;
+    }
+
     //
     // C++: size_t Mat::step1(int i = 0)
     //
@@ -1271,6 +1295,9 @@ public class Mat {
 
     private static native long n_reshape(long nativeObj, int cn);
 
+    // C++: Mat Mat::reshape(int cn, int newndims, const int* newsz)
+    private static native long n_reshape_1(long nativeObj, int cn, int newndims, int[] newsz);
+
     // C++: Mat Mat::row(int y)
     private static native long n_row(long nativeObj, int y);
 
@@ -1294,6 +1321,9 @@ public class Mat {
     // C++: Size Mat::size()
     private static native double[] n_size(long nativeObj);
 
+    // C++: int Mat::size(int i)
+    private static native int n_size_i(long nativeObj, int i);
+
     // C++: size_t Mat::step1(int i = 0)
     private static native long n_step1(long nativeObj, int i);
 

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

@@ -817,6 +817,19 @@ public class MatTest extends OpenCVTestCase {
         assertMatEqual(truth, dst);
     }
 
+    public void testReshapeIntIntArray() {
+        Mat src = new Mat(6, 5, CvType.CV_8UC3, new Scalar(0));
+        assertEquals(2, src.dims());
+        assertEquals(src.rows(), src.size(0));
+        assertEquals(src.cols(), src.size(1));
+
+        int[] newShape = {1, src.channels() * src.cols(), 1, src.rows()};
+        dst = src.reshape(1, newShape);
+        assertEquals(newShape.length, dst.dims());
+        for (int i = 0; i < newShape.length; ++i)
+            assertEquals(newShape[i], dst.size(i));
+    }
+
     public void testRow() {
         Mat row = gray0.row(0);
         assertEquals(1, row.rows());