Abstract: A process for format conversion of DCT macroblocks in an MPEG video bitstream that are divided into blocks, each of which includes a plurality of microblocks. In each DCT block, the significant frequencies are identified and preserved, isolating a corresponding microblock preferably consisting of the microblock on the top left of each block and setting to zero the coefficients of the remaining microblocks. On the microblock thus isolated there is performed an inverse discrete cosine transform, and the microblock thus obtained is merged with the homologous microblocks obtained from the other blocks comprised in a respective starting macroblock, so as to give rise to a merging block. The merging block thus obtained undergoes a discrete cosine transform so as to obtain a final block, which can be assembled into a macroblock with converted format.

Abstract: The present invention relates to an improved surveillance system, more particularly to a surveillance system having the function of driving the camera for the scanning and tracking automatically by using a control panel, a motor controller, and a driver to drive the motor. Such motor works together with a rotary disc and a camera lens as well as a restricting switch to compute and memorize the direction and angle of rotation of the motor by the sensing signal.