Discrete sine transform

About: Discrete sine transform is a research topic. Over the lifetime, 3269 publications have been published within this topic receiving 73181 citations.

An efficient lossless robust watermarking scheme by integrating redistributed invariant wavelet and fractional Fourier transforms

Abstract: An ensemble lossless watermarking scheme is proposed in the present study by integrating different concepts like redistributed invariant wavelet transform, discrete fractional Fourier transform, singular value decomposition (SVD) and visual cryptography within the framework of a single algorithm The invariant wavelet transform helps to obtain the transform domain, which is invariant to flipping and rotation of image, this is followed by discrete fractional Fourier transform to obtain the translation invariant domain Finally, embedding positions are selected based on a key and reliable features are extracted by performing SVD on a window centered at these positions Based on these reliable features a binary map is generated through which a master share is created The corresponding ownership share is produced from the master share and the watermark In verification process the same operations of the embedding process are applied to the test image to obtain the master share and the watermark is recovered by stacking it over the ownership share There are two main features of the proposed scheme (1) The quality of the image to be watermarked do not degrade during the process and (2) the extracted watermark can still be identified even from a seriously distorted image These findings are also demonstrated with the help of a comparative study with several related schemes

Prime-factor DCT algorithms

Abstract: In this correspondence, new algorithms are presented for computing the l-D and 2-D discrete cosine transform (DCT) of even length by using the discrete Fourier transform (DFT). A comparison of the proposed algorithms to other fast ones points out their computational efficiency, which is mainly based on the advantages of prime-factor decomposition and a proper choice of index mappings. >

A separable Hartley-like transform in two or more dimensions

Abstract: This letter introduces a discrete, separable, real-to-real transform, called the cas-cas transform. Theorems for the two-dimensional (2-D) case are presented, and the cas-cas transform is compared to the Hartley transform as an alternative way to convolve 2-D arrays and compute 2-D power spectra.

A generalized architecture for the one-dimensional discrete cosine and sine transforms

Abstract: In this paper, we propose a generalized architecture for the 1-D discrete cosine transform (DCT), discrete sine transform (DST), and their inverses based on a general formulation. This architecture provides the flexibility to adaptively select different transform functions through a simple control signal. As compared with other unified architectures for the DCT/DST, the proposed architecture possesses better performance in the hardware cost and the number of I/O channels. The proposed design can be efficiently realized by using the distributed arithmetic approach in the VLSI implementation.

Restoration of images degraded by motion blur and noise

Abstract: This paper considers the restoration of images degraded by a motion blur in the presence of noise. Based on a two-dimensional separable autoregressive image model, a one-dimensional horizontally causal vector state space model with multiple delays is derived. By the discrete sine transform, the one-dimensional vector state space model is decomposed into a set of nearly uncorrelated scalar subsystems, to which the Kalman filter is applied to obtain an approximate recursive computationally efficient restoration algorithm for motion degraded images. The same technique is also applied to a semicausal minimum variance image model in order to derive a related recursive restoration algorithm. The computational efficiency is accomplished by the discrete sine transform and the transform data compression technique. Numerical results are presented to show the applicability of the algorithms developed. Finally, the possible extension of the present method to the case of general blur is suggested.