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 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 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.Item Comparison of OMP and SOMP in the reconstruction of compressively sensed hyperspectral images(2011) Aravind, N.V.; Abhinandan, K.; Acharya, V.V.; Sumam, David S.In this paper, we present a novel method for the acquisition and compression of hyperspectral images based on two concepts - distributed source coding and compressive sensing. Compressive sensing (CS) is a signal acquisition method that samples at sub Nyquist rates which is possible for signals that are sparse in some transform domain. Distributed source coding (DSC) is a method to encode correlated sources separately and decode them together in an attempt to shift complexity from the encoder to the decoder. Distributed compressive sensing (DCS) is a new framework suggested for jointly sparse signals which we apply to the correlated bands of hyperspectral images. We compressively sense each band of the hyperspectral image individually and can then recover the bands separately or using a joint recovery method. We use the Orthogonal Matching Pursuit (OMP) for individual recovery and Simultaneous Orthogonal Matching Pursuit (SOMP) for joint decoding and compare the two methods. The latter is shown to perform consistently better showing that the Distributed Compressive Sensing method that exploits the joint sparsity of the hyperspectral image is much better than individual recovery. � 2011 IEEE.Item Comprehensive address generator for digital signal processing(2009) Kini, M.R.; Sumam, David S.Computational efficiency of Signal Processing Algorithm implemented in hardware depends on efficiency of datapath, memory speed, and generation of addresses for data access. In case of signal processing applications, pattern of data access is complex in comparison with other applications. If implemented in a general purpose processor, address generation for signal processing applications will require execution of a series of instructions and use of datapath elements like adders, shifters etc. In general, considerable processor resources and time are utilized. It is desirable to execute one loop of a kernel per clock. This demands generation of typically three addresses per clock: two addresses for data sample/coefficient and one for storage of processed data. A set of dedicated, efficient Address Generator Units (AGU) will definitely enhance the performance. This paper focuses on design and implementation of Address Generators for complex addressing modes required by Multimedia Signal Processing algorithms. Among other addressing modes, a novel algorithm is developed for accessing data in a Bit-Reversed order for Fast Fourier Transforms (FFT), and Zig-zag order for Discrete Cosine Transforms (DCT). When mapped to hardware, this scales linearly in gate complexity with increase in the size and uses less components. �2009 IEEE.Item 3D Estimation and visualization of motion in a multicamera network for sports(2011) Kumar, A.; Chavan, P.S.; Sharatchandra, V.K.; Sumam, David S.; Kelly, P.; O'Connor, N.E.In this work, we develop image processing and computer vision techniques for visually tracking a tennis ball, in 3D, on a court instrumented with multiple low-cost IP cameras. The technique first obtains 2D ball tracking data from each camera view using 2D object tracking methods. Next, an automatic feature-based video synchronization method is applied. This technique uses the extracted 2D ball information from two or more camera views, plus camera calibration information. In order to find 3D trajectory, the temporal 3D locations of the ball is estimated using triangulation of correspondent 2D locations obtained from automatically synchronized videos. Furthermore, in order to improve the continuity of the tracked 3D ball during times when no two cameras have overlapping views of the ball location, we incorporate a physics-based trajectory model into the system. The resultant 3D ball tracks are then visualized in a virtual 3D graphical environment. Finally, we quantify the accuracy of our system in terms of reprojection error. � 2011 IEEE.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.