[BC: ]

The [BC: ] modifier changes the colors in the given area of the picture (or in the whole picture, if all the <X>, <Y>, <W>, <H> parameters are missing). Both the posible brightness and contrast changes are in a scale from -1 to 1. One can specify the values also as percent values - if the <Brightness> and <Contrast> values are below -1.0 or above 1.0, then the values will be divided by 100.0 before using them.