In this letter, we discuss a recursive optimization approach for the subband synthesis windowing component used in all three layers of the MPEG-1 and -2 audio decoding frameworks. We explain the design of the proposed algorithm and briefly discuss how it can be combined with other novel and existing optimization strategies. The impact of these optimizations on the number of multiplications and additions is shown, and the influence of the algorithm on the amount of memory required by the adapted decoder is also discussed. We show that the proposed algorithm offers very interesting possibilities for implementing efficient VLSI designs.

This paper discusses a recursive optimization approach for the subband synthesis windowing component used in all three layers of the MPEG-1 and −2 audio decoding standards. First, we explain the design of the proposed algorithm and illustrate how it can be combined with other optimization strategies that have already been discussed in the literature. Next, we discuss how the recursive optimizations reduce the required number of multiplications which often restrict the possibilities for implementing efficient hardware designs. Finally, we summarize the influence of the algorithm on the amount of memory required by the decoder.

We present a method to detect roads and building boundaries on high resolution aerial photographs. These image features are found through the use of a line detection algorithm that is based on the three following steps: first, pre-smoothing, to remove noise and possibly irrelevant small scale details; this is followed by an automatic threshold of the gradient magnitude, thus generating a binary edge map; and in order to detect straight lines, this edge map is then used as the input of the Hough transform. We describe these steps with particular emphasis on the gradient threshold and show typical results obtainable with this method.

An investigation is made on the compatibility of the video formats, standard TV (625/50/2:1/4:3), EDTV (625/50/1:1/16:9), HDTVint (1250/50/2:1/16:9) and HDTVpro (1250/50/1:1/16:9) in three-dimensional subband coding. A hierarchical method is proposed leading to a more reasonable joint solution for the issues of digital transmission evolution and interlace-to-progressive scanning conversion in the frame work of bit rate compression. Conventional HDTVint with the diamond shaped spectrum is proposed to be replaced by a kind of "switching" HDTVint signal which consists of three components and motion detection bits (MDB). The first component and the MDB represent TV. The first plus the second component and the MDB represent EDTV. HDTVpro is split into switching HDTVint and an extra component. The switching threshold and the length of temporal filter banks are discussed. Rearranging the pixels in subbands is recommended. Based on the proposed method, the transmission system can evolve through four steps: TV, EDTV, HDTVint, and HDTVpro. Results of bit rate compression are also presented. TV, EDTV, HDTVint, and HDTVpro are compressed to approximately 40, 80, 128, and 256 Mb/s, respectively. Interlace scanning has drawbacks such as line flicker and line crawling as the eye follows the line structure in the picture. Progressive version switching TV and HDTVint could be reconstructed using one frame memory without the problems of handling temporal-vertical diamond shaped spectra of conventional TV and HDTVint based on one-frame memory algorithm in the receiver.>

In the above named work by B. Girod et al. (see ibid., vol.36, no.3, p.332-46, 1988), a stability condition for a DPCM (differential pulse code modulation) system with additional quantization error noise shaping has been proposed. In the present work, a correction of this stability condition is derived.>

In the above correspondence, two algorithms for the construction of a minimum redundancy code have been described. In this correspondence, it is pointed out that the strategy in the correspondence does not always lead to an optimal code. A correction of both algorithms is presented.

This paper deals with a generalized stop-and-wait ARQ scheme, whereby data blocks are sent to the receiver in sets containing an arbitrary number of identical copies. The main idea behind this scheme is a reduction of the idle time of the transmitter.

In this paper a formula is derived for the capture ratio of an FM demodulator of which the finite bandwidth has been taken into account. The results obtained in a numerical example are in complete agreement with the measurements made on a physical detector.