updateBrightnessContrast 88 samples/cpp/demhist.cpp createTrackbar("brightness", "image", &_brightness, 200, updateBrightnessContrast); updateBrightnessContrast 89 samples/cpp/demhist.cpp createTrackbar("contrast", "image", &_contrast, 200, updateBrightnessContrast); updateBrightnessContrast 91 samples/cpp/demhist.cpp updateBrightnessContrast(0, 0);