Digital signal

About: Digital signal is a research topic. Over the lifetime, 44213 publications have been published within this topic receiving 345279 citations.

Fractal block coding of digital video

Abstract: A video coding method is proposed which is based upon fractal block coding The method utilizes a novel three-dimensional partitioning of input frames for which a number of efficient block-matching search methods can be used, and permits spatio-temporal splitting of the input blocks to improve overall-encoding quality After describing the basic fractal block coding algorithm, the details of the proposed three-dimensional algorithm are presented along with encoding and decoding results from two standard video test sequences, representative of video-conferencing data These results indicate that average compression rates ranging from 40 to 77 can be obtained with subjective reconstruction quality of video-conferencing quality The results also indicate that, in order to meet the compression rates required for very low bit rate coding, it is necessary to employ additional techniques such as entropy encoding of the fractal transformation coefficients >

Quadrantal symmetry associated with two-dimensional digital transfer functions

Abstract: The class of two-dimensional (2-D) digital transfer functions which possess quadrantal symmetry in their frequency responses is derived. Application of this class in the design of 2-D recursive digital filters is indicated.

Method and apparatus for receiving and / or reproducing digital signals

Abstract: A method and apparatus is provided for receiving and/or reproducing a digital signal, capable of efficiently recording a compressed, packeted digital signal (170-173) and inhibiting a copy thereof. An input packet signal is added (Fig. 9) with a time stamp indicating a relative time of an arrival of the packet, and the packet signals of digital information with the added time stamps are recorded at reduced intervals (Fig. 8(3)) therebetween. In reproducing, a packet interval adjusting circuit (Fig. 11) restores the original packet intervals in accordance with the time stamps, and then a time stamp change circuit (Fig. 9) changes at least one bit of the time stamp and thereafter outputs the digital information.

Arrangement for decoding digital video signals

Abstract: The invention relates to an arrangement for deriving an ancillary signal from a compressed digital video signal (eg MPEG) The ancillary signal comprises selected parts of the main signal, for example, the DC coefficients of I-pictures, or the unscrambled parts The ancillary signal thus obtained can be used for display in a (multi-) picture-in-picture television receiver, or as an 'appetizer' in order to encourage the user to pay a subscription fee The ancillary signal can separately be recorded in digital video recorders so as to assist the user in finding the beginning of a scrambled program on tape The ancillary signal can also be generated at the transmitter end and transmitted at a low bit rate A decoder for decoding such an ancillary signal is considerably simpler and less expensive than a full-spec MPEG decoder

High-level algorithm and architecture transformations for DSP synthesis

Abstract: This survey paper reviews numerous high-level transformation techniques which can be applied at the algorithm or the architecture level to improve the performance of digital signal and image processing architectures and circuits implemented using VLSI technology. Successful design of VLSI signal and image processors requires careful selection of algorithms, architectures, implementation styles, and synthesis techniques. High-level transformations can play an important role in reducing silicon area or power at the same speed or in increasing the speed for same area. These transformations can also increase the suitability of an algorithm for a particular architectural style. The transformation techniques reviewed in this paper include pipelining, parallel processing, retiming, unfolding, folding, look-ahead, relaxed look-ahead, associativity, distributivity, and reduction in strength.