displayed in the form of a thumbnail image in an email transmission mode or an email reception mode a camera unit 140 includes a camera sensor and a signal processor the camera sensor photographs image data and converts photographed optical signals into electric signals the signal processor converts analog image signals photographed by the camera sensor into digital data it is assumed that the camera sensor is a charge coupled device ccd sensor the signal processor may be realized by a digital signal processor dsp further the camera sensor may be integrated with the signal processor or the camera sensor may also be constructed separately from the signal processor an image processor unit 150 generates screen data for displaying image signals output from the camera unit 140 the image processor unit 150 processes the image signals which are output from the camera unit 140 by the frame and outputs the frame image data according to the characteristics and sizes of a display unit 160 the image processor unit 150 includes an image codec compresses the frame image data which is displayed on the display unit 160 by a predetermined scheme or restores the compressed frame image data into the original frame image data the image codec may include a jpeg codec.