A video data transmission method which is able to transmit compressed video data along with uncompressed video data determines whether any compressed data needs to be transmitted when transmitting uncompressed video data. When the compressed data needs to be transmitted, all pixels in each frame of the uncompressed video data are analyzed and one color which is dominant according to the number of pixels receiving it is obtained. The compressed data is inserted into the data for the relevant large number of pixels and the video data is transmitted to a receiving device after insertion of the compressed data.