sniekum/ar_track_alvar — pull request #40 by k-okada (2014-11-19 14:54:45+00:00)
Title: fix calib_K using roi info,

Some robots, for example Baxter publishes camera_info with roi
```
$ rostopic echo -n 1 /cameras/right_hand_camera/camera_info
header:
seq: 2468773
stamp:
secs: 1416402182
nsecs: 127162000
frame_id: /right_hand_camera
height: 400
width: 640
distortion_model: plumb_bob
D: [0.0153369206277, -0.0432553402055, -0.00118657118488,
-0.00147661359656, 0.00896220693898]
K: [403.911583563, 0.0, 631.065444573, 0.0, 403.911583563,
375.688877091, 0.0, 0.0, 1.0]
R: [1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0]
P: [403.911583563, 0.0, 311.06544457300004, 0.0, 0.0,
403.911583563, 175.688877091, 0.0, 0.0, 0.0, 1.0, 0.0]
binning_x: 1
binning_y: 1
roi:
x_offset: 320
y_offset: 200
height: 400
width: 640
do_rectify: False

```
so we need to consider roi into intrinsic camera parameters.
see https://github.com/ros-perception/vision_opencv/blob/groovy-devel/image_geometry/src/pinhole_camera_model.cpp#L137