1. An image processing apparatus comprising: an acquisition unit configured to acquire an image; a first composition unit configured to generate a first composite image by compositing the acquired image and a previous image which is acquired before the acquired image at a first composition ratio and to generate a second composite image by compositing the acquired image and the previous image at a second composite ratio; a first generation unit configured to generate an image obtained by emphasizing high frequency components in the first composite image as a high frequency component emphasized image; a second generation unit configured to generate an image which has reduced high frequency components in the second composite image as a low frequency component image; a second composition unit configured to generate a third composite image by compositing the high frequency component emphasized image and the low frequency component image at a third composite ratio and to generate a fourth composite image by compositing the high frequency component emphasized image and the low frequency component image at a fourth composite ratio; an output unit configured to alternately output the third composite image and the fourth composite image as sub-frame images of the acquired image; and a composite ratio adjustment unit configured to adjust the first composite ratio, the second composite ratio, the third composite ratio, and the fourth composite ratio for respective frames.