An electronic device, a method and a storage medium are disclosed. The electronic device includes a processor and a memory operatively coupled to the processor. The processor is configured to receive a user input from an external electronic device. The processor is also configured to synthesize a first region that is a first partial region of a first raw image and a second partial region of a second raw image based on the user input to generate a composite raw image. The processor is further configured to modify at least one of a first attribute of the first raw image and a second attribute of the second raw image to generate a third attribute. Additionally, the processor is configured to calibrate the composite raw image using the third attribute to generate a composite image.