An image processing apparatus such as a digital camera and a method of controlling the same is provided. In one embodiment, the digital camera generates an HDR image by combining two of a plurality of images to be combined for normal HDR processing. Before image combining operation, the digital camera converts the tone characteristics of at least one of the two images so as to assign more tone values to a tone area of an entire tone area of the HDR image which is not properly covered by either of the two images than before conversion.