PURPOSE: To enhance a compression rate and to improve the efficiency of an image file device by providing a noise elimination means to eliminate noise of an original image data and a compression means to compress an image data after noise elimination processing to the system.

CONSTITUTION: An original image data is stored in a buffer 2, and noise elimination processing is applied to the original image data. That is, black level dots at upper/lower/left/right/diagonal directions with respect to a black level dot of the image data are counted, and as to dots at ends and corners of frames, dots located at the outside of the frame are all set to white level dots, and when number of black dots is 2 or below, a middle black dot is regarded as noise and eliminated. The result is stored in a buffer 4, and the image data from which the noise is eliminated is subject to compression by the MH system or the MR system. That is, consecutive white and black level dots in the image data are coded as one data, and then number of data is reduced and the compression is attained.