An image processing apparatus according to the present invention includes a plurality of input units configured to correspond to respective image data items to be obtained, an obtaining unit configured to obtain the image data items corresponding to the input units when the input units are operated, a determination unit configured to determine, when one of the input units is operated within a predetermined period of time, layout for displaying a corresponding one of the image data items in a display unit, and configured to determine, when at least two of the input units are operated within the predetermined period of time, layout for displaying image data items corresponding to the operated input units in the display unit in parallel, and an output unit configured to generate display data for a single screen using at least one of the image data items obtained using the obtaining unit in accordance with the layout determined using the determination unit and output the display data to the display unit.