title: Update camera intrinsic parameter in open3d-python
body: <p>I am trying to use Open3D library in python to plot a 3D model. My issue is that I am not able to update the camera intrinsic properties. I would like to know how to do it - if its possible. Currently its using default camera parameters.</p>
  <pre><code>rgbd_image = o3d.geometry.RGBDImage.create_from_tum_format(color_raw, depth_raw)
  
  a = o3d.camera.PinholeCameraIntrinsicParameters
  pcd = o3d.geometry.PointCloud.create_from_rgbd_image(
          rgbd_image,
          o3d.camera.PinholeCameraIntrinsic(
              o3d.camera.PinholeCameraIntrinsicParameters.Kinect2DepthCameraDefault))
  # Flip it, otherwise the pointcloud will be upside down
  pcd.transform([[1, 0, 0, 0], [0, -1, 0, 0], [0, 0, -1, 0], [0, 0, 0, 1]])
  o3d.visualization.draw_geometries([pcd])
  </code></pre>
  <p>I would like to update the intrinsic matrix to [3131.58 0.00 1505.62 , 0.00 3131.58 2004.13, 0.00 0.00 1.00]</p>
  <p>Thanks.</p>