Challa S. Sastry

Associate Professor

Department of Mathematics, IIT Hyderabad

csastry (AT) iith (DOT) ac (DOT) in
Office: 503, C-Block
Phone (Office): +91 40 2301 6072


Wavelets, Sparse Representation Theory and Inverse Problems



  • Education: PhD[IIT Kanpur], M.Sc(Tech) [JNTU Hyderabad], B.Sc[Hindu College, Machilipatnam; Nagarjuna University]
  • PhD dissertation: Wavelet based multiresolution methods in Computerized Tomography (Advisor: Prof. P.C.Das)
  • Professional Experience: Gained at University of Hyderabad, University of British Columbia, Canada and IIITDM Jabalpur (about 2 years at each place), before joining IIT Hyderabad.




Journal Publications:


  • “Sparse description of overdetermined linear systems via a new matrix factorization method,” Submitted (with P. Theeda and P. Jampana)


  • “Construction of Incoherent Frames as Union of Orthonormal Bases,” Submitted (with P. Sasmal, P. Theeda, P. Jampana).


  • “Generalized Euler Squares and Application in Compressed Sensing,” Submitted (with P. Sasmal and P. Jampana).


  • Sparse recovery analysis of preconditioned frames via convex optimization,” Submitted (with P. Sasmal, P. Theeda and P. Jampana).


  • “Dictionary-based Monitoring of Premature Ventricular Contractions: An Ultra-Low-Cost Point-of-Care Service,” To appear in Artificial Intelligence in Medicine, 2018 (with B.S. Chandra, L. Anumandla and S. Jana).


  • “Reconstruction of Sparse-View Tomography via Preconditioned Radon Sensing Matrix,” To appear in J. of Applied Maths & Comp. 2018 (with P. Theeda, P. Kumar and P. Jampana)


  • "Composition of binary compressed sensing matrices," IEEE Signal Processing Letters, Vol. 23, 1096-1100, August 2016, (with P. Sasmal, R. Naidu, P.V. Jampana)


  • "Deterministic Compressed Sensing matrices: Construction via Euler Squares and Applications," IEEE Transactions on Signal Processing, Vol. 64, 3566-3575, July 2016, (with R. Naidu, P.V. Jampana)


  • "Reliable Resource-Constrained Telecardiology via Compressive Detection of Anomalous ECG Signals," Computers in Biology and Medicine, Volume 66, 144-153, 2015 (with S. Chandra and S. Jana).


  • "Content based medical image retrieval using dictionary learning, " Neurocomputing, Vol. 168, 880-895, 2015 (with M. Srinivas, R. Naidu and C. K. Mohan)


  • "In-plane rotation and scale invariant simultaneous dictionary learning and clustering,"  IEEE Trans. on Image Processing, 22(6), 2013, (with Y. Chen, V. Patel, J.   Philips and R. Chellappa)


  • "Spectral dynamics and regularization of incompletely and irregularly measured data," DEDS, Springer, Vol.  19(3), pp: 181-197, 2011.



Conference Proceedings:


  • “Minimally scaled and incoherent frames,” To appear in Proc. of IEEE-ICSIP, 2018, China (with P. Theeda, P. Sasmal and P. Jampana).


  • “Reconstruction of sparse-view tomography via banded matrices, In LNCS, Vol. 10481, In proc. of ICVGIP, IIT Guwahati, 2016 (with P. Theeda, Praveen Kumar and P. Jampana).


  • "On the existence of equivalence class of RIP compliant matrices, " (In proc. of 11th SampTA, Washington, May 2015, with P. Sasmal and P. Jampana).


  • "Optimization of low-dose tomography via binary sensing matrices, " In Proc. of 17th IWCIA, ISI Calcutta, [Volume 9448, 337-351, Lecture Notes in Computer Science] (with T. Prasad, P. Kumar and P. Jampana).


  • "Reliable Low-Cost Telecardiology: High-Sensitivity Detection of Ventricular Beats using Dictionaries, " In Proc. 16th IEEE Healthcom, Natal, Brazil, 2014.," (with B. Chandra and S. Jana)


  • "Multivariable polynomials for the construction of binary sensing matrices," In Proc. of CMCGS, Singapore, February 2014 (with R. Naidu and P.V.Jampana)


  • "Telecardiology: Hurst exponent based anomaly detection in compressively sampled ECG Signals," In Proc. of 15th  IEEE HealthCom, Lisbon, Portugal, 2013 (with S. Chandra and S. Jana)


  • "Reconstruction from divergent ray projections," (In Proc. of SPIE Imaging, San Francisco, USA, 2012, with S. Singh)


  • "Rotation invariant simultaneous clustering and dictionary learning for image retrieval," In Proc. of IEEE-ICASSP, Kyoto, Japan, 2012 (with Y.Chen, V.Patel, J. Philips, R.Chellappa).


  • "Characterization of ECG signals using multiscale approach," In Proc. of IEEE-SPCOM, 2012, IISc Bangalore, (with K.S. Veena, P.Gupta, M. Amarnath)




Recent developments at the intersection of algebra and optimization theory -- by the name of Compressed Sensing/Compressive Sampling Theory -- aim at providing linear systems with sparse descriptions. These developments are found to have potential for several applications. My current research interests lie in Frame theory, Sparsity promoting optimization techniques and their applications. My previous research, nevertheless, was directed toward Wavelets, Reconstruction problems in tomography and the Analysis of data networks.





Wavelets & Applications, Linear algebra, Numerical  Linear Algebra, Numerical Analysis, Probability Theory, Theory of Frames, Image Processing, Digital Signal Processing, Sparse Repesentaion Theory (Partly) and UG (B.Tech) level Math Courses.



                                                                 RESEARCH GUIDANCE (Guided/Co-guided)



·         Dr. R. Ramunaidu

·         Dr. P. Sasmal

·         Mr. Prasad Theeda (Thesis Submitted)

·         Mr. Munnu Sonkar (Pursuing)

·         Ms. K. Z. Nazia (Pursuing)