Added a sharpening filter into the dithering function.
Added a sharpening filter into the dithering function.



Former-commit-id: 55edd7561873bd0c29ddab2a2cb55ea3ed1b1fa1
Former-commit-id: 6e02f76f48a86124fb1ca606ae41f4bc9a382c85
kobolabs/qt-everywhere-4.8.0,kobolabs/qt-everywhere-4.8.0,kobolabs/qt-everywhere-4.8.0,kobolabs/qt-everywhere-4.8.0,kobolabs/qt-everywhere-4.8.0,kobolabs/qt-everywhere-4.8.0,kobolabs/qt-everywhere-4.8.0,kobolabs/qt-everywhere-4.8.0,kobolabs/qt-everywhere-4.8.0,kobolabs/qt-everywhere-4.8.0