title: How to multiply 2 matrices in java and then use the result as transformation matrix for Imgproc.warpPerspective function
body: <p>I want to create 3 matrices:
  A of 3x4 and B of 4x4 and C of 4x3 . Then I want to multiply them D = A * (B * C) to receive a 3x3 matrix
  And then call warpPerspective with D.
  All of the above is needed to be done with Java. In c++ it is 'extremely' easy opposed to Java, I could not find any real example for Java implementation.</p>