The Qt Creator "IDE" allows third party documentation to be used. However, I have not found OpenCV documentation in the required format. Apparently it is also possible to generate such a file from HTML documentation: http://qt-project.org/doc/qt-4.8/qthelp-framework.html
But OpenCV uses Sphinx for documentation: http://docs.opencv.org/ Sphinx could generate those files but I don't know how this works: http://sphinx-doc.org/builders.html#sphinx.builders.qthelp.QtHelpBuilder
The documentation (generator) sources are at: https://github.com/Itseez/opencv/tree/master/doc
Qt says at http://qt-project.org/wiki/Qt_Creator_Documentation_Gallery#df49adab93b9e0c10c64f72458b31971 "CMake 3.0.0 and upwards can use Sphinx to generate a .qch file. "