The present invention relates to an image data transmission, and in particular, to a data transmission VNC image processing method. The present invention addresses the problems in the prior art, there is provided a data processing method for transmitting image VNC, it may be determined by the method of the embodiment of the image data of the rectangular pixel and the attribute value change vector, and compression algorithm, so that the image transmission occupies smaller data bandwidth, and the transmission efficiency is improved, so that the mobile data terminal, or a portable device receives the response speed becomes faster. The present invention is determined by the properties of the rectangular image data and the pixel value variation vector processing algorithm. The present invention is applied to an image transmission field VNC.