1. An image display device in a digital TV, comprising: a data processing part for executing bit map conversion, compression, restoration and format-conversion for text data; a memory for storing the bit map data obtained according to the bit map conversion and compression in said data processing part and image data inputted from an arbitrary receiving part, and the receiving part receives either digital image data or analog image data; an image outputting part for reading the image data from the memory; and a display processing part for mixing the image data read from the image outputting part and the bit map data converted into format by the data processing part.