A method for determining compensating data voltages for a liquid crystal display panel. The liquid crystal display panel includes a liquid crystal cell defined by a first substrate and a second substrate arranged opposite to each other. The liquid crystal cell has non-uniform cell gaps across the cell. The method includes: measuring a capacitance distribution across the liquid crystal cell; determining a cell gap distribution across the cell based on the capacitance distribution; and deriving, from the cell gap distribution, respective compensation voltages for different data voltages for each of different regions of the liquid crystal cell.