Solidity is the official language for ethereum. I wander that can this language process images or would it support library like OpenCV?
There is currently no built-in Solidity support for images at all, and there is currently no library to do so. And as it stands now, if you wrote the library yourself, it would cost too much gas.
There are currently no plans to add image processing to the Solidity language.
It is in general a good idea to do as much work as possible off-chain, and only use on-chain Solidity code for verification and sending, receiving and storing currency.