1. A display control apparatus comprising: a processor; and a memory coupled to the processor to store instructions that cause the processor to perform operations of at least one of a plurality of units of the display control apparatus including: a synthesizing unit configured to synthesize a plurality of image data to generate synthesized image data; an image quality adjustment unit configured to carry out image quality adjustment for the synthesized image data output from the synthesizing unit; a format discrimination unit configured to discriminate a format of each of the plurality of image data; a determination unit configured to determine referenced image data for the image quality adjustment among the plurality of image data based on discrimination results in the format discrimination unit; a control unit configured to control the image quality adjustment unit so as to carry out the image quality adjustment for the synthesized image data using an image quality adjustment parameter suitable for the referenced image data determined by the determination unit; and a face detection unit configured to carry out face detection for each of the plurality of image data, wherein the determination unit determines the referenced image data for the image quality adjustment by further using the detection result in the face detection unit.