An electronic device and a method thereof are provided for processing stored images to reconstruct a high-resolution image. The electronic device includes an image sensor configured to acquire an image through a plurality of pixels including a first pixel set and a second pixel set; and a processor configured to acquire at least one first image through the first pixel set; acquire at least one second image through the second pixel set; and generate at least one third image according to a selected mode for generating the at least one third image, by using the at least one first image and the at least one second image.