window system doesn't support opengl (raspberry pi)

问题发生：

在树莓派上使用opencv的时候，出现如下错误：

window system doesn't support opengl

经过定位，发现是在cvShowImage出现该错误的，经过分析，原因是树莓派系统装的是opengl的简易版，所以不支持cvShowImage，解决方法如下Solutions.

转自：http://raspberrypi.stackexchange.com/questions/40438/opencv-display-image-window-system-doesnt-support-opengl

Problem：

I have a project which uses the raspberry pi camera and openCV to do some movement analysis. However, when I want to display the image (with the openCV API or a ROS node), there’s an error saying

window system doesn't support opengl

Solutions：

Raspberry Pi doesn’t come with OpenGL support by default, but it’s a simple installation. I believe you will just need to install libgl1-mesa-dri. You can do that at the command line using: Code:

$  apt-get update
$  apt-get install libgl1-mesa-dri