An image processing method for facilitating data transmission is provided. An image compression method is performed to convert X-bits binary digital signals to a binary compressed data in a floating-point form of (1.n)*2.sup.m. Bit m represents the first bit with logic level "1" of the X-bits binary digital signals, and n represents the bits taken from the X-bits binary digital signals after the bit m. The binary compressed data in the floating-point form of (1.n)*2.sup.m is outputted with a sequence of binary number representing a set of (m, n). The latter n bits of the sequence of binary numbers are consisted of the n bits of the X-bits digital signal. Therefore, by the present image compression method, the transmission amount of image data is reduced. The transmission time of image data and the volume of a memory for storing the image data are also reduced.