Sanghoon Lee

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Previously, fovcated video compression algorithms have been proposed which, in certain applications, deliver high-quality video at reduced bit rates by seeking to match the nonuniform sampling of the human retina. We describe such a framework here where foveated video is created by a nonuniform filtering scheme that increases the compressibility of the(More)
Most image and video compression algorithms that have been proposed to improve picture quality relative to compression efficiency have either been designed based on objective criteria such as signal-to-noise-ratio (SNR) or have been evaluated, post-design, against competing methods using an objective sample measure. However, existing quantitative design(More)
To provide a lifelong supply of blood cells, hematopoietic stem cells (HSCs) need to carefully balance both self-renewing cell divisions and quiescence. Although several regulators that control this mechanism have been identified, we demonstrate that the transcription factor PU.1 acts upstream of these regulators. So far, attempts to uncover PU.1's role in(More)
This paper explores the problem of communicating high-quality, foveated video streams in real time. Foveated video exploits the nonuniform resolution of the human visual system by preferentially allocating bits according to proximity to assumed visual xation points, thus delivering perceptually high quality at greatly reduced bandwidths. Foveated video(More)
We describe a method for achieving perceptually minimal video distortion over packet-erasure networks using perceptually unequal loss protection (PULP). There are two main ingredients in the algorithm. First, a perceptual weighting scheme is employed wherein the compressed video is weighted as a function of the nonuniform distribution of retinal(More)
The transcription factor PU.1 is an important regulator of hematopoiesis; precise expression levels are critical for normal hematopoietic development and suppression of leukemia. We show here that noncoding antisense RNAs are important modulators of proper dosages of PU.1. Antisense and sense RNAs are regulated by shared evolutionarily conserved(More)
It is generally recognized that severe video distortions that are transient in space and/or time have a large effect on overall perceived video quality. In order to understand this phenomena, we study the distribution of spatio-temporally local quality scores obtained from several video quality assessment (VQA) algorithms on videos suffering from(More)