Provided is an image processing apparatus which includes a block histogram generation unit configured to calculate frequency of a pixel value in each block, divide a dynamic range, and generate a first histogram including “N” number of bins, a pixel histogram generation unit configured to calculate frequency of a target pixel in a block based on first histograms of the block including the target pixel and a block adjacent to the block including the target pixel, and generate a second histogram including “N” number of bins for each pixel, and an output value determination unit configured to generate a relation between the pixel value and an output value of the pixel value based on the second histogram so that a maximum cumulative frequency of the second histogram matches a maximum value of the output value, and calculate the output value based on the pixel value of the target pixel.