1. An electronic device, comprising: a camera module that captures a plurality of images of an object; a processor: and a storing module storing one or more programs, which when executed by the processor, cause the processor to: select two images having maximal edge response values and combine the two images having maximal edge response values according to a rate of the two edge response values; detect an edge response value of a combined image; store the combined image and the edge response value of the combined image; select two images having maximal edge response values from the combined images and uncombined images, and combine the two images until all of the images are combined.