opencv-3.3.0 cv_bridge
===
環境: ubuntuMATE raspberry pi3
/usr/local/lib/
裡面同時有opencv-3.1.0, opencv-3.3.0

#### 問題：
程式裡面同時要用兩種版本opencv,
比如a function 用opencv-3.3.0
b function用opencv3.1.0
會有這種需求是因為cv_bridge kinetic版本是opencv-3.1.0編的 假使要使用最新3.3.0的函式（我想寫一個dnn ROS package）

#### 情形
cv_bridge 在3.3.0build from source 一直有錯誤 就想說有沒有別招XD

跟這個討論很相關的
https://github.com/ros-perception/vision_opencv/issues/162

錯誤

Project 'cv_bridge' specifies '/opt/ros/kinetic/include/opencv-3.2.0-dev'
  as an include dir, which is not found.  It does neither exist as an
  absolute directory nor in
  '/opt/ros/kinetic//opt/ros/kinetic/include/opencv-3.2.0-dev'.  Ask the
  maintainer 'Vincent Rabaud <[e-mail]>' to fix it.

這是找不到header的錯誤

#### 想法
3.3.0在pkg-config有設定
能夠用pkg-config指定opencv版本,然後單獨去鍊結 libcv_bridge.so?

現在是編譯時候會當掉

/opt/ros/kinetic/lib/libcv_bridge.so

cmake_minimum_required(VERSION 2.8.3)
project(ssdmobilenet)

find_package(catkin REQUIRED COMPONENTS
  cv_bridge
  image_transport
  roscpp
  rospy
  sensor_msgs
  std_msgs
)
#find_package(OpenCV 3 REQUIRED)
find_package(PkgConfig)
pkg_check_modules(OpenCV REQUIRED opencv)

catkin_package(
    INCLUDE_DIRS include
    CATKIN_DEPENDS cv_bridge
)


include_directories(
  ${catkin_INCLUDE_DIRS}
# ${OpenCV_INCLUDE_DIRS}
)

add_executable( ssdmobilenet src/ssd_mobilenet_object_detection.cpp)

target_link_libraries(
        ssdmobilenet
	${catkin_LIBRARIES}
#	${OpenCV_LIBRARIES}
)

ref:
https://github.com/ros-perception/vision_opencv/issues/162

https://answers.ros.org/question/261819/problem-with-catkin_make/

https://github.com/jsk-ros-pkg/jsk_recognition/issues/2033

https://hackmd.io/s/S1oIlawDb#

###### tags: `opencv3.3.0`