An image processing apparatus includes a first correction amount acquiring unit and a first correction unit. The first correction amount acquiring unit acquires a first luminance correction amount of each block based on the luminance of each pixel in the block obtained by dividing a first image among multiple processing target images obtained by imaging a target object with multiple sheets bound together while opening the target object. The first correction unit corrects the luminance of each pixel in the multiple processing target images based on the first luminance correction amount of each block acquired by the first correction amount acquiring unit.