Digital images in their uncompressed form require an enormous amount of storage capacity. Such uncompressed data needs large transmission bandwidth for the transmission over the network. Discrete Cosine Transform (DCT) is one of the widely used image compression method and the Discrete Wavelet Transform (DWT) provides substantial improvements in the quality of picture because of multi resolutio...

DCT-based transforms are widely adopted for video compression. Recently, many authors have highlighted that prediction residuals usually have directional structures that cannot be efficiently represented by conventional Discrete Cosine Transform (DCT). Although directional transforms have superior performance over the conventional DCT, for application in video compression it is necessary to eva...

The use of shape-adaptive transforms is a popular approach for coding arbitrarily shaped objects in image/video coding due to their adaptability at object edges and low complexity. In this respect shape adaptive DCT (SA-DCT) and shape adaptive DWT (SA-DWT) have been proposed in previous literature. The Integer Transform (IT), a derivative of the 4x4 DCT, has been adopted in the latest H.264/AVC...

This paper presents a cost-effective processor core design that features the simplest hardware and is suitable for discrete cosine transform/indiscrete cosine transform (DCT/IDCT) operations in H.263 and digital camera. This design combines the techniques of fast direct two-dimensional DCT algorithm, the bit-level adder-based distributed arithmetic, and common subexpression sharing to reduce th...

The Discrete Tchebichef Transform (DTT) which based on discrete orthogonal Tchebichef polynomials can be an alternative to the Discrete Cosine Transform (DCT) for image processing such as image compression and image recognition as the properties of the DTT are similar to that of the DCT. The DTT not only has higher energy compactness than the DCT in images that have high illumination value vari...

Appearance-based feature extraction constitutes the dominant approach for visual speech representation in a variety of problems, such as automatic speechreading, visual speech detection, and others. To obtain the necessary visual features, typically a rectangular region-of-interest (ROI) containing the speaker’s mouth is first extracted, followed, most commonly, by a discrete cosine transform (...

—This paper proposes new concepts of the windowed all phase biorthogonal transform (WAPBT), which is inspired by the all phase biorthogonal transform (APBT). In the light of windowed all phase digital filter theory, windowed all phase biorthogonal transforms is proposed. The matrices of WAPBT based on DFT, WHT, DCT and IDCT are deduced, which can be used in image compression instead of the con...

We undertake a study of the performance difference of the discrete cosine transform (DCT) and the wavelet transform for gray scale images. Wide range of gray scale images were considered under seven different types of images. Image types considered in this work are standard test images, sceneries, faces, misc, textures, aerials and sequences. Performance analysis is carried out after implementi...

New lapped transforms are introduced. The LBT (lapped biorthogonal transform), and HLBT (hierarchical lapped biorthogonal transform) are appropriate for image coding, and the MLBT (modulated lapped biorthogonal transform) and NMLBT (nonuniform modulated lapped biorthogonal transform) are appropriate for audio coding. The HLBT has a significantly lower computational complexity than the LOT (lapp...

Systolic arrays are a family of parallel computer architectures capable of using a very large number of processors simultaneously for important computations in applications such as scientific computing and signal processing. A discrete cosine transform (DCT) expresses a sequence of finitely many data points in terms of a sum of cosine functions at different frequencies. DCT is a Fourier-related...