2. Conference Papers
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Item Quality and complexity comparison of H.264 intra mode with JPEG2000 and JPEG(2004) Aravind, A.L.; Rao, B.P.; Kudva, S.S.; Babu, S.; Sumam, David S.; Rao, A.V.The recently proposed H.264 video coding standard offers significant coding gains over previously defined standards. An enhanced intra-frame prediction algorithm has been proposed in H.264 for efficient compression of I-frames. This paper investigates the scope of the intraframe coder of H.264 for image coding. We compare the quality of this coder and the complexity of its decoder with the commonly used image codecs (JPEG and JPEG2000). Our results demonstrate that H.264 has a strong potential as an alternative to JPEG and JPEG2000. �2004 IEEE.Item Pipelined implementation of high radix adaptive CORDIC as a coprocessor(2016) Oza, S.S.; Shah, A.P.; Thokala, T.; Sumam, David S.The Coordinate Rotational Digital Computer (CORDIC) algorithm allows computation of trigonometric, hyperbolic, natural log and square root functions. This iterative algorithm uses only shift and add operations to converge. Multiple fixed radix variants of the algorithm have been implemented on hardware. These have demonstrated faster convergence at the expense of reduced accuracy. High radix adaptive variants of CORDIC also exist in literature. These allow for faster convergence at the expense of hardware multipliers in the datapath without compromising on the accuracy of the results. This paper proposes a 12 stage deep pipeline architecture to implement a high radix adaptive CORDIC algorithm. It employs floating point multipliers in place of the conventional shift and add architecture of fixed radix CORDIC. This design has been synthesised on a FPGA board to act as a coprocessor. The paper also studies the power, latency and accuracy of this implementation. � 2015 IEEE.Item Performance analysis of compensation current extraction techniques for 3?, 3-wire shunt active power filter under unbalanced supply(2009) Gondat, J.M.; Anantha, Adithya, V.; Sumam, David S.Actve power filters are effective in mitgating line current harmonics and compensating for the reactive power in the line. Many papers comparing the performance of active power filter extraction algorithms are found in the literature, but there is explicit mention about the suitability of any particular extraction algorithm under all conditions. Hence this paper is an attempt to compare the performance of direct methods of compensating current extraction algorithms for three-phase active power filters under different conditions of mains supply using Matlab/Simulink�. Both transient and steady state conditions are considered. The compensating techniques under analysis are: synchronous detection method, sychronous reference frame method, id-iq method, instantaneous active reactive power theory (p-q theory) modied p-q theory, adaptive noise cancellation, notch filtering and Fourier based sinusoidal subtraction algorithms. Under balanced conditions all the compensatng techniques give proper result, but under balanced conditions only few of the compensating techniques work satisfactorily. In fact the equal resistance synchronous detection method and Fourier based sinusoidal subtraction algorithms perform better under extreme conditions. With proper implementation, sinusoidal subtraction algorithm performs better under both transient and steady state conditions. � 2009 IEEE.Item Multilevel coset coding of video with Golay codes(2011) Aparna, P.; Sumam, David S.This paper presents a video coding method based on the principle of distributed source coding. This work aims in shifting the encoder complexity to the decoder to support uplink friendly video applications, simultaneously achieving the rate-distortion performance of the conventional predictive coding system. In this work concept of syndrome coding with Golay codes is adopted for compression. The simulation results presented in this paper reveals the superior performance of this distributed video coder over the Intraframe coders and predictive coders for video data with less correlation between frames. � 2011 IEEE.Item Estimation of attack time constant for dynamic range compressors in hearing AIDS(2016) Deepu, S.P.; Sumam, David S.; Ramesh, Kini, M.Dynamic Range Compression (DRC) is a key component in all modern Hearing AIDS. Attack and Release time constants decide the speed with which the DRC should act to the incoming signal amplitude variation. So an accurate estimation of time constants gives a precise control over the DRC behavior. In this paper we examined various errors that occur in the output of the DRC while using conventional methods which affect attack and release time constants adversely. New methods are proposed for a better estimation of time constants in DRC. Since all the modifications are made in the estimation of attack time, there is no need to change the existing hardware for DRC. The proposed algorithm gives perfect output characteristics with zero error for test signals defined in ANSI S3.22 standards for hearing aid specifications. � 2016 IEEE.Item Low cost black box for cars(2013) Patil, C.; Marathe, Y.; Amoghimath, K.; Sumam, David S.Automotive electronics plays a significant role in the automobile industry and provides luxurious features and more importantly addresses the safety and security concerns. The work presented in this paper aims at providing a cost effective solution to the design and development of an event data recorder which has been basically adopted from the aviation sector considering the need and the correlated benefits. The paper presents an integrated design of the black box with the basic features of the data recorder which could be very useful for domestic vehicles and at the same time it also hosts several additional features that could assist in mitigating the number of accidents, or at bare minimum, will serve as an analysis tool to prevent future accidents by analyzing the previous accidents. The black box also provides automatic accident notification system which helps in informing the nearest hospital and the traffic authority by providing not only the coordinates of the accident but also the exact physical address for immediate medical attention which can save numerous lives every day. The black box also hosts several other features like CAN compatibility, attractive user console and advanced web tracking anytime and from anywhere. Thus the overall cost is highly optimized by integrating such multiple features. � 2013 IEEE.Item Irreversible wavelet compression of radiological images based on visual threshold(2016) Chandrika, B.K.; Aparna, P.; Sumam, David S.Visually lossless irreversible coding permit compression algorithms to improve the compression gain without disturbing the visual image quality. This paper proposes a novel coding scheme in which wavelet based visual model is embedded into lossless compression algorithm to compress the volumetric medical image data. Obtained experimental results are compared with numerically lossless compression schemes such as Differential Pulse Code Modulation (DPCM), Joint Photographic Experts Group-Lossless (JPEG-LS), JPEG-2000 and High Efficiency Video Coding (HEVC). The proposed method achieves reduced bit rate without deteriorating the visual quality of the resulting images. � 2015 IEEE.Item Improved algorithms for implementation of MPEG2 AAC decoder on FPGA(2005) Shenoy, R.R.; Naik, S.S.; Sumam, David S.This paper discusses methods to implement the IMDCT filter bank, Noiseless decoder, Inverse quantiser and Scale factor application modules of MPEG-2 Advanced Audio Coding decoder more efficiently when implemented on FPGAs. The efficiency of the algorithms has been validated through implementation on Xilinx Virtex II FPGAs.Item Implementation of JPEG2000 still image codec on blackfin (ADSP - BF535) processor(2004) Kiran, K.S.; Shivaprakash, H.; Subrahmanya, M.V.; Raj, S.; Sumam, David S.With increasing use of Multimedia in everyday life, there is a need not only for better image compression techniques which can be used in a wide range of applications but also for efficient implementation of these compression algorithms on power-efficient platforms. To cater to such needs several compression methodologies have been proposed and standardized. We have implemented, JPEG2000, an emerging standard for still image compression on the Analog Devices Blackfin Digital Signal Processor (DSP). Implementation of still-image compression on programmable DSPs offer several advantages like ease of changing the codec standard, improved value addition by customizing the codec to the target application, scalability in image sizes etc. This paper presents the implementation details of the JPEG2000 still image codec on ADSP-BF535 processor based Analog Devices EZ-kit Lite board, and the quality of the results obtained demonstrate the potential of the low-power Micro-Signal Architecture of Blackfin processor as a good choice for embedded multimedia applications.Item Implementation of JPEG2000 still image codec on blackfin (ADSP - BF535) processor(2004) Kiran, K.S.; Shivaprakash, H.; Subrahmanya, M.V.; Raj, S.; Sumam, David S.With increasing use of Multimedia in everyday life, there is a need not only for better image compression techniques which can be used in a wide range of applications but also for efficient implementation of these compression algorithms on power-efficient platforms. To cater to such needs several compression methodologies have been proposed and standardized. We have implemented, JPEG2000, an emerging standard for still image compression on the Analog Devices Blackfin Digital Signal Processor (DSP) Implementation of still-image compression on programmable DSPs offer several advantages like ease of changing the codec standard, improved value addition by customizing the codec to the target application, scalability in image sizes etc. This paper presents the implementation details of the JPEG2000 still image codec on ADSP-BF535 processor based Analog Devices EZ-kit Lite board, and the quality of the results obtained demonstrate the potential of the low-power Micro -Signal Architecture of Blackfin processor as a good choice for embedded multimedia applications.