In this paper image compression using hybrid wavelet transform is proposed. Hybrid wavelet transform matrix is formed using two component orthogonal transforms. One is base transform which contributes to global features of an image and another transform contributes to local features. Here base transform is varied to observe its effect on image quality at different compression ratios. Different ...

Lifting scheme based integer transforms are very powerful tools to construct lossless coding schemes. These transforms such as the Integer Fast Fourier Transform (IntFFT) and the Integer Modified Discrete Cosine Transform (IntMDCT) are integer approximations of the original floatingpoint transforms, and hence there is an approximation error in the transform domain. This paper will propose struc...

Principal Component Analysis (PCA) approaches to image recognition are data dependent and computationally expensive. To classify unknown images they need to match the nearest neighbour in the stored database of extracted image features. In this paper, Discrete Cosine Transforms (DCTs) are used to reduce the dimensionality of image space by truncating high frequency DCT components. The remaining...

In this paper, regular fast algorithms for discrete cosine transform (DCT) and discrete sine transform (DST) of types II–IV are proposed and mapped onto pipeline architectures. The algorithms are based on the factorization of transform matrices described earlier by Wang. The regular structures of the algorithms are advantageous when mapping them onto hardware although such algorithms do not rea...

This paper presents an overview of the latest transform and quantization designs for H.26L. Unlike the popular discrete cosine transform (DCT) used in previous standards, the transforms in H.26L can be computed exactly in integer arithmetic, thus avoiding inverse transform mismatch problems. The new transforms can also be computed without multiplications, just additions and shifts, in 16-bit ar...

This paper proposes a method to neutralize the pose of facial databases. Efficient use of the feature extractors and its properties leads to the pose neutralization. Feature extractors discussed here are few transforms like Discrete Cosine Transform (DCT) and Discrete Fourier Transform (DFT). Symmetric behavior of transforms is the basis of the proposed method. Modulo based approach in extracti...

The discrete cosine transform (DCT) is a Fourier-related transform similar to the discrete Fourier transform (DFT), but using only real numbers. It is equivalent to a DFT of roughly twice the length, operating on real data with even symmetry (since the Fourier transform of a real and even function is real and even), where in some variants the input and/or output data are shifted by half a sampl...

A unified architecture for radix-2 decimation-in-time fast Fourier transform and inverse discrete cosine transform of type II is presented based on constant geometry formulation of the algorithms. The parallelism of the architecture can be specified to meet various throughput and area requirements. The type and size of the transform in the architecture can be configured in run-time. In addition...

Abstract: This paper presents a strategy to design bilinear discrete cosine transform (DCT) algorithms of prime lengths. We show that by using multiplicative groups of integers, one can identify and arrange the computation as a pair of convolutions. When the DCT length p is such that (p−1)/2 is odd, the computation uses two (p−1)/2 point cyclic convolutions. When (p − 1)/2 = 2q with m > 0 and q...

A polynomial transform is the multiplication of an input vector x ∈ C by a matrix Pb;α ∈ Cn×n; whose ðk;lÞth element is defined as plðαkÞ for polynomials plðxÞ ∈ C1⁄2x from a list b 1⁄4 fp0ðxÞ; : : : ; pn−1ðxÞg and sample points αk ∈ C from a list α 1⁄4 fα0; : : : ;αn−1g. Such transforms find applications in the areas of signal processing, data compression, and function interpolation. An import...