The resolution of a low-resolution image is made high and a stereoscopic image is displayed. Resolution is made high by super-resolution processing. In this case, the super-resolution processing is performed after edge enhancement processing is performed. Accordingly, a stereoscopic image with high resolution and high quality can be displayed. Alternatively, after image analysis processing is performed, edge enhancement processing and super-resolution processing are concurrently performed. Accordingly, processing time can be shortened.