In H.264/AVC [1], integer transforms are applied instead of the 8×8 discrete cosine transform (DCT) of previous standards to avoid inverse transform mismatch problems. However, these transforms make it difficult to transcode the precoded video contents with the earlier video coding standards into H.264/AVC in DCT-domain, thus causing cascaded re-encoding in the pixel-domain. There are strong re...

Progressive transmission of images based on lapped orthogonal transform (LOT), adaptive classification and human visual sensitivity (HVS) weighting is proposed. HVS weighting for LOT is developed using a general technique that can be applied to any orthogonal transform. The method is compared with discrete cosine transform (DCT) based progressive image transmission (PIT). It is shown that LOT b...

Abstract: In this study, an efficient approach for detecting zero-quantised discrete cosine transform (DCT) coefficients for video coding is developed. Compared with conventional detection methods of zero-quantised DCT coefficients used in H.264/AVC, the proposed algorithm has two major features. First, a new classification of patterns for DCT, quantisation, inverse quantisation and inverse dis...

Discrete cosine transform (DCT) is widely used in many practical image/video compression systems because of its compression performance and computational efficiency. This work adopts DCT, and modified the SPIHT algorithm that designed initially for encoding the discrete wavelet transform (DWT) coefficients in order to suit to encode DCT coefficients. The algorithm represents the DCT coefficient...

We present algorithms for the type-IV discrete cosine transform (DCT-IV) and discrete sine transform (DSTIV), as well as for the modified discrete cosine transform (MDCT) and its inverse, that achieve a lower count of real multiplications and additions than previously published algorithms, without sacrificing numerical accuracy. Asymptotically, the operation count is reduced from 2N log2 N +O(N...

|In this paper, we propose uni ed systolic arrays for computation of the 1-D and 2-D discrete cosine transform/discrete sine transform/discrete Hartley transform (DCT/DST/DHT). By decomposing the transforms into evenand odd-numbered frequency samples, the proposed architecture computes the 1-D DCT/DST/DHT. Compared to the conventional methods the proposed systolic arrays exhibit advantages in t...

Discrete Cosine Transform (DCT) has similar performance to the Karhunen-Loeve Transform (KLT) & same properties to the Discrete Fourier Transform (DFT). It is advantageous for speech enhancement as it provides better energy compaction capability. Though there is a perfectly stationary signal, frame to frame variations of DCT coefficients are observed. In pitch synchronous analysis DCT based spe...

-The discrete Legendre transform is compared to the discrete cosine transform (DCT), which is based on Chebyshev polynomials, in terms of image compression efficiency. Using standard test images in various image compression configurations, the DCT is found to perform marginally better than the discrete Legendre transform in all cases examined. A simplified fundamental matrix theory for construc...

In this paper, the PSNR performance of conventional discrete cosine transform (DCT) OFDM system is compared with discrete wavelet transform (DWT)-OFDM system. We use different error correcting codes viz; Reed Solomon, LDPC, DCT and DWT. KeywordsDCT, DWT, OFDM, Reed Solomon, LDPC.