Harsh Dhand

A Compression scheme for archiving DNA sequencing images

DNA sequencing today produces vast amounts of image data in the final recording process. For example, Solexapsilas sequencing by synthesis platform allows the outcome of sequencing reactions to be observed simultaneously at a resolution of millions of individual DNA molecules. Recording the outcome after each reaction therefore, generates terabytes of image data in the course experimentation. For posterity reasons some of this image data needs to be preserved for longer term and therefore we need compression schemes with high compression ratios while data fidelity needs to be preserved. This paper describes the design and implementation of a novel compression scheme for archiving DNA Sequencing Images produced during the sequencing by synthesis procedure. The scheme is based on the identification of information points in the sequencing images, and regeneration of the whole image using these, exploiting diffraction characteristics of point sources of light. It provides for a high compression ratio of 1:10 to 1:20, while still maintaining acceptable fidelity of the information.

Towards obtaining an ideal real time panoramic video

Panoramic image construction is a well known image processing technique, which allows capturing of a large field of view in one single image or video. Panoramic video construction from videos captured from multiple cameras pose interesting challenges to the existing panoramic image construction algorithms. Computation time and quality of video output are major issues in panoramic videos. While the time of computation is required to meet basic real-time constraints of video streams, the quality should be good enough such that the stream can be used for the purposes intended. In this work, we quantify the various stages in panoramic image construction. We propose various intra-frame and inter-frame optimizations on the top of basic panoramic image construction algorithm and a methodology to achieve real-time panoramic videos.

New approach to architectural synthesis: incorporating QoS constraint

Embedded applications like video decoding, video streaming and those in the network domain, typically have a Quality of Service (QoS) requirement which needs to be met. Apart from being a design constraint, it can also be considered as a flexibility that the design does not have to work under worst case data condition. For example, in the case of video decoding with variable decoding time for individual frames, it may be adequate that only a fraction of frames (say 90%) needs to be decoded. In this work, we propose a novel method of exploiting this flexibility for efficient partitioning and mapping in the architectural synthesis of the application at hand. We translate QoS specification of the overall application to the time constraint on the individual components constituting the application and use this knowledge in an optimum synthesis technique based on Mixed Integer Linear Programming (MILP). We study this in the context of MPEG2 Decoder and show that the approach can be used to obtain optimal time of execution as well as energy reduction while meeting the QoS requirements.