1. An image processing apparatus that performs soft focus processing on an image, the image processing apparatus comprising: a first acquisition unit configured to acquire an input image; a second acquisition unit configured to acquire a shooting condition for the acquired input image; a generation unit configured to generate a plurality of blurred images different in degree of blur from the same acquired input image; a synthesis unit configured to synthesize the acquired input image and at least one of the blurred images generated by said generation unit; a storage unit configured to store a synthesis ratio table including a set of predetermined synthesis ratios that are predetermined for a plurality of input images different in size from one another to achieve substantially the same soft focus effects regardless of the size of the acquired input image; and a setting unit configured to set a synthesis ratio between the images to be synthesized using the synthesis ratio table, according to the size of the acquired input image.