K. V. S. S. Prasad Rao

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The modified discrete cosine transform (MDCT) is employed in subband/transform coding schemes as the analysis/synthesis filter bank based on time domain aliasing cancellation (TDAC). The most efficient implementation of the forward and inverse MDCT computation for layer III in MPEG-1 and MPEG-2 international audio coding standards is proposed. It is based(More)
JPEG is a popular DCT-based still image compression standard, which has played an important role in image storage and transmission since its development. Several papers have been published to improve the performance of JPEG. Advanced image coding (AIC) combines intra frame block prediction from H.264 with a JPEG-style DCT, followed by context adaptive(More)
Blocking artifacts are visible in the decoded frames of most video coding standards at low bit rate coding. Latest video coding standard H.264/AVC uses an in-loop deblocking filter to remove the blocking artifacts. The main drawback of this filter is its high implementation complexity. In this paper, we propose an in-loop deblocking filter to remove the(More)
This paper presents a region of interest (ROI) based H.263 compatible video codec, which combines the idea of object-based coding from MPEG4 visual into the traditional block-based H.263 codec. A face detection and tracking scheme with very low complexity is proposed to segment human face from video conferencing sequences in real-time. With the segmentation(More)
Several human visual system (HVS) based quality metrics have been developed in recent years to measure the quality distortions caused by digital image coding techniques. Because of the complicated nature of the HVS characteristics, these metrics do not provide acceptable correlation with perceptual evaluations of the distortion. Recent studies by the Visual(More)
This paper discusses approximation noise shaping to improve the efficiency of the integer modified discrete cosine transform (IntMDCT)-based lossless audio codec. The scheme is applied to rounding operations associated with lifting steps to shape the noise spectrum towards the low frequency bands. In this paper, constraints on the noise shaping filter and a(More)
The objective of this paper is to develop a technique for transcoding from MPEG-2 main profile to H.264 main profile and compare its performance with other transcoding architectures. The proposed transcoder reuses information from the MPEG-2 bit stream taking into account the improved approaches such as multiple block size motion estimation, in loop(More)
We propose a modified hybrid DCT-SVD image-coding system (MHDCTSVD) to encode both monochromatic and color images. The color (RGB) components are transformed into YCbCr. Cb and Cr components are downsampled by a factor of two along both the horizontal and vertical directions. The standard deviation of 8/spl times/8 blocks of the Y component is used to(More)
The lifting scheme-based integer fast Fourier transform (IntFFT), an integer approximation of the FFT, is reversible. When it is used for lossless coding applications, the computational complexity and approximation error increase due to realization of the trivial butterflies by three lifting steps. Since the error appears as a "noise floor" and it limits(More)