I think so.
There are only a few modules which are not BSD. I can remember SIFT, but may be others...
Added info
Since OpenCV forces people to add stuff under BSD license, unless specifically stated otherwise in special licenses, the following rules apply
// Copyright (C) 2013, OpenCV Foundation, all rights reserved.
// Third party copyrights are property of their respective owners.
//
// Redistribution and use in source and binary forms, with or without modification,
// are permitted provided that the following conditions are met:
//
// * Redistribution's of source code must retain the above copyright notice,
// this list of conditions and the following disclaimer.
//
// * Redistribution's in binary form must reproduce the above copyright notice,
// this list of conditions and the following disclaimer in the documentation
// and/or other materials provided with the distribution.
//
// * The name of the copyright holders may not be used to endorse or promote products
// derived from this software without specific prior written permission.
So basically you can do anything you want with it, as long as you keep the copyright notice!