An image processing apparatus according to an embodiment of the present invention includes a correction interval setting unit for setting a correction interval; a correction interval dividing unit for dividing the correction interval into a black side interval and a white side interval; histogram calculating units for calculating a total number of luminance histograms of the black side interval and the white side interval, respectively; gain setting units for setting gains of a γ curve for raising the luminance and a γ curve for lowering the luminance, respectively; gamma curve generating units for generating a gamma curve for raising the luminance and a gamma curve for lowering the luminance, respectively; a gamma curve combining unit for combining the gamma curve for raising the luminance and the gamma curve for lowering the luminance; and a luminance conversion unit for performing the luminance conversion process using the combined gamma curve.