Originally Posted by estabroo
you need to #include <stdlib.h> to get the prototype for exit
So far as I can tell, badriinvenkat ignored that answer and reposted the same warning messages.
Originally Posted by badriinvenkat
1) Learn how to use CODE tags, so you can post readable code samples.
2) I assume you downloaded something that you used as a basis for that code. You shouldn't expect us to recognize OpenCV code. Instead you should post the URL that gave you the information that you misunderstood to produce that code.
3) To use OpenCV, you need to install libraries for OpenCV. It is best to install those through your distribution's package manager. You use Mint, right? I don't have easy access to the package info for Mint, so I checked packages.ubuntu.com, which probably has the same package names you need for Mint. I also haven't used OpenCV, so I'm not sure exactly which packages you need. But I think you need some or all of these packages:
I've never used OpenCV, but from a quick web search it appears you can't use cvShowImage that way. You need to specify both the window and the image and I think you need to have created the window in a previous call before you do the cvShowImage.