release版的程序必须调用release版的opencv lib，
debug版的程序必须调用debug版的opencv lib，
否则，opencv里imread等函数会运行出错
最近用opencv2.2以上版本，尝试采用C++风格来编程。
发现最简单的 imread, imshow 都出错了。
最后发现问题。
release版的程序必须调用release版的opencv lib，
opencv_core242.lib
opencv_legacy242.lib
opencv_highgui242.lib
opencv_features2d242.lib
opencv_flann242.lib
opencv_calib3d242.lib
opencv_imgproc242.lib
opencv_video242.lib
debug版的程序必须调用debug版的opencv lib，
opencv_core242d.lib
opencv_legacy242d.lib
opencv_highgui242d.lib
opencv_features2d242d.lib
opencv_flann242d.lib
opencv_calib3d242d.lib
opencv_imgproc242d.lib
opencv_video242d.lib