There is provided an image processing apparatus. An obtaining unit obtains a first image to which tone conversion processing conforming to a first input/output characteristic having a first maximum output luminance value has been applied. A generation unit generates first correction information for correcting a luminance value of the first image based on a difference regarding an output luminance value between the first input/output characteristic and a second input/output characteristic having a second maximum output luminance value, and on second correction information for correcting a luminance value of a second image to which tone conversion processing conforming to the second input/output characteristic has been applied. A correction unit corrects a luminance value of the first image in conformity to the first correction information.