1. An electronic device for previewing dual-shot images, comprising: a display screen; a first image sensor configured to capture a front image; a second image sensor configured to capture a rear image; and an image signal processor configured to perform image processing on images captured by the first and second image sensors; a controller configured to: store in a memory at least one trained object detectable within the front image, in response to a portion of a user of the electronic device being captured within the front image, setting the portion of the user as a subject part within the front image, in response to failing to detect the portion of the user within the front image, searching for the at least one trained object in the front image and if the at least one trained object is found, setting the at least one trained object as the subject part within the front image, set an area of pixels of interest based on algorithmic recognition of the subject part within the front image, the area of pixels of interest enclosing the subject part, output from the first image sensor a partial image based on the set area of pixels of interest and create, using the image signal processor, a combined image by overlaying the partial image on the rear image, and transmit the combined image to the display screen for display.