A method of converting an output picture, useable by a digital versatile disk (DVD) player connected to a digital television via a communication cable includes receiving output picture conversion information after data communication with the digital television commences; transmitting predetermined image picture information to the digital television while an output image of the DVD reproducing signal is being converted in response to the output picture conversion information; and interrupting the transmission of the picture information and transmitting the converted output picture to the digital television when the conversion of the output picture is completed. The abnormal picture generated while the resolution or the aspect ratio of the output image is being converted is blocked, and a predetermined picture is output to prevent viewing the abnormal picture.