1. A method of displaying an image on a portable image device, the method comprising: receiving a first input indicative of an input associated with an application; generating a first image object in a buffer of the portable image device in response to the first input, the first image object corresponding to a screen capture of an execution screen of the application and being of a first image format; storing the first image object in a memory of the portable image device; generating a first image using the first image object stored in the memory of the portable image device, the first image being of a second image format different from the first image format; and displaying the first image on an image display device of the portable image device.