A set of DCT domain properties for shifting and scaling by real amounts, and taking linear operations such as differentiation is described. The DCT coefficients of a sampled signal are subjected to a linear transform, which returns the DCT coefficients of the shifted, scaled and/or differentiated signal. The properties are derived by considering the inverse discrete transform as a cosine series...

DCT-based digital video coding standards such as MPEG and H.26x are becoming more widely adopted for multimedia applications. Since the standards differ in their format and syntax, video transcoding, where a pre-coded video bit-stream is converted from one format to another format, is of interest for purposes such as channel bandwidth adaptation and video composition. DCT-domain video transcodi...

The presented paper presents the statistical analysis of the diagonal dct coefficients of facial images in order to identify the face from the data base. The dct coefficients matrix contains the frequency variations of facial images in three parts; the lower half of the matrix that contains the low frequency elements that make up the flashy part of the face, the upper half that contain the high...

A new content-dependent fast discrete cosine transform (DCT) algorithm is introduced. Since it requires less than half of the samples of an 8 8 block as input and produces only the rst three DCT coe cients, it is far less complex than conventional full fast DCT algorithms. It is shown that these three coe cients are su cient for the majority of the blocks for motion-compensated low bit-rate vid...

Discrete Cosine transform (DCT) is an important tool in digital signal processing. In this paper, a novel algorithm to perform DCT multiplierlessly is proposed. First, by modular mapping and truncating Taylor series expansion, the DCT is expressed in the form of the product of the constants and discrete moments. Second, by performing appropriate bit operations and shift operations in binary sys...

In a typical MC-DCT encoding scheme, a large portion of the bit rate is used to encode the location and amplitude information of the nonzero quantized DCT coe cients. Therefore e cient encoding of the DCT coe cients is extremely important. In this paper we describe the Joint Position-Dependent Encoding (PDE) approach to encode the DCT coe cients. Joint PDE exploits the variations in statistical...

We have cloned and sequenced a chicken cDNA encoding an l-DOPAchrome tautomerase (DCT) from an embryonic melanocyte cDNA library. The chicken DCT gene encodes a deduced protein of 516 amino acids (aas) and shares 69.2% and 69.9% aa sequence identity with the deduced mouse and human DCT proteins, respectively. Northern blot hybridisation analysis reveals a DCT transcript of 3.5kb in RNA from the...

The discrete cosine transform (DCT) has a variety of applications in image and speech processing. The idea of the subband{DFT (SB{DFT) [1], [2] is applied in [3] to the DCT. In this paper the basic idea of the SB{DCT is discussed which is based on subband decomposition of the input sequence. Approximation is done by discarding the computations of bands of little energy. The complexity of this f...

The discrete cosine transform (DCT) and the discrete sine transform (DST) have found wide applications in speech and image processing, as well as telecommunication signal processing for the purpose of data compression, feature extraction, image reconstruction, and ltering. In this paper, we present new recursive algorithms for the DCT and the DST. The proposed method is based on certain recursi...

MPEG has recently issued a CFP for voluntary fixed point 8x8 IDCT and DCT standards to ease the effort that is needed to implement the IDCT and DCT, and also to help ensure that decoders are implemented in conformance with the MPEG standard. This paper is conclusion and extension of our previous proposal responding to the CFP. A systematic approach of fixed point 8x8 IDCT and DCT design and imp...