Conference Papers
Permanent URI for this collectionhttps://idr.nitk.ac.in/handle/123456789/28506
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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 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 Improved algorithms for implementation of MPEG2 AAC decoder on FPGA(Institute of Electrical and Electronics Engineers Inc., 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 Automatic speech recognition using audio visual cues(2004) Yashwanth, H.; Mahendrakar, H.; Sumam David, S.Automatic speech recognition (ASR) systems have been able to gain much popularity since many multimedia applications require robust speech recognition algorithms. The use of audio and visual information in the speaker-independent continuous speech recognition process makes the performance of the system better compared to the ones with only the audio information. There has been a marked increase in the recognition rates by the use of visual data to aid the audio data available. This is due to the fact that video information is less susceptible to ambient noise than audio information. In this paper a robust Audio-Video Speech Recognition (AVSR) system that allows us to incorporate the Coupled Hidden Markov Model (CHMM) model for fusion of audio and video modalities is presented. The application records the input data and recognizes the isolated words in the input file over a wide range of Signal to Noise Ratio (SNR.) The experimental results show a remarkable increase of about 10% in the recognition rate in the AVSR compared to the audio only ASR and 20% compared to the video only ASR for an SNR of 5dB. ©2004 IEEE.Item A system level solution for power quality problems(2005) Padiyar U, U.H.; Mahant-Shetti, S.S.M.; Sumam David, S.The power quality deterioration is still an unsolved problem due to the increased power electronic load getting into the system. Every, consumer friendly equipment is power electronic controlled in one-way or other. The current drawn by all of these equipments are generally non-sinusoidal in nature, and are distorting the voltage wave as well. Many solutions proposed so far, though found useful in some cases have never become a system solution for the power quality deterioration problem. This paper proposes a unique innovative solution to these problems by a correction at the generation level by changing the shape of source wave keeping in view the nature of new loads. This paper presents PSPICE® simulated results to justify the need for source wave shape change, which will act as a system level solution to the limit peak currents drawn by the new generation power electronic loads. © 2006 IEEE.Item Adaptive local cosine transform for seismic image compression(2006) Aparna., P.; Sumam David, S.A typical seismic analysis involves collection of data by an array of seismometers, transmission over a narrow-band channel, and storage of data for analysis. Transmission and archiving of large volumes of data involves great cost. Hence there is a need to devise suitable methods for compressing the seismic data without compromising on the quality of the reconstructed signal. This paper presents our work on the seismic data compression based on adaptive local cosine transform and its associated multi-resolution and best-basis methodology and compares the results with wavelet based implementation. © 2006 IEEE.Item Underdetermined blind source separation using binary time-frequency masking with variable frequency resolution(2008) Anandkumar, A.J.G.; Aneesh Ghosh, T.A.; Damodaram, B.T.; Sumam David, S.A novel method based on an algorithm by Pedersen et. al. using independent component analysis and binary time-frequency masking to iteratively segregate sources from a stereo recording is proposed here to improve the quality of estimated sources and reduce artifacts (musical noise). The inspiration comes from research in auditory scene analysis which indicates that the human auditory system uses a spectrogram-like time-frequency representation with variable frequency resolution for performing stream segregation and perceptual grouping. A time-frequency transform with a variable frequency based on the discrete cosine transform and amplitude modulation is suggested. A method for perfect reconstruction and a way to exploit short-time stationarity of the sources have also been suggested. Simulation results indicate significant improvements in objective evaluation criteria like percentage of energy loss and signal-to-noise ratio improvement. Subjective listening tests indicate a marked improvement in estimated signal quality with strongly reduced artifacts.Item Syndrome coding of video with LDPC codes(2008) Reddy, S.; Aparna., P.; Sumam David, S.In this paper we present the simulation results of the video coding system based on the principle of distributed source coding. Unlike conventional video coding system, this system exploits source statistics at the decoder, thus reversing the complexity model. Current implementation uses LDPC codes for syndrome coding. © 2008 IEEE.Item A system level solution to improve VRM efficiency(2009) Padiyar U, H.; Sumam David, S.; Mahant-Shetti, S.S.M.An investigation of the synchronous buck regulator working as a Voltage regulator module (VRM) for Processor power supply applications, under light load condition is presented. VRM, a very special case of power supply belongs to switched mode power supply family. Important design specifications include low output voltage with extremely small tolerance band, high load current of large slew rates, small foot print, low cost etc. Higher operating efficiencies are desired to enable extended battery mode operation in mobile platforms in addition to reducing heat dissipation. This paper identifies the source of energy inefficiency and suggests a variable frequency approach as a cost effective system level solution, to enhance the efficiency of the converter supplying widely varying load with special emphasis to light load operation.