A video processing method comprises the steps of dividing an entire input data
region into three of first, second and third regions in order from the low level
side thereof; setting, as an output data characteristic to input data, a trapezoidal
characteristic which is nonlinear and continuous as a whole and consists of a linear
portion in the first region where the gain is greater than one, a linear portion
in the second region where the gain is equal to one exactly or approximately, and
a linear portion in the third region where the gain is smaller than one; setting,
as another output data characteristic to the input data, an S-shaped characteristic
which is nonlinear and continuous as a whole and consists of linear portions in
the first and third regions where the gain is smaller than one, and a linear portion
in the second region where the gain is greater than one; selecting either the trapezoidal
characteristic or the S-shaped characteristic; and correcting the digital luminance
data in accordance with the selected characteristic. This method eliminates the
known disadvantages and increases the luminance of a reproduced image while raising
the contrast of its dark portion.