This paper presents a fast and efficient way for color reindexing that tends to maximize the compression performance of a palette-based compression system. The proposed scheme relates the index difference of neighboring pixels to the potential cost of bits. It optimizes the assignment of index values to colors in a one-step look-ahead greedy fashion. Experimental results suggest that the propos...

Neurogenic pulmonary edema is a serious and always life-threatening complication following several lesions of the central nervous system. We report an experiment with 58 Wistar-Hanover adult male rats. Two groups were formed: control (n=4) and experimental (n=54). The experimental group sustained acute midthoracic spinal cord injury by Fogarty's balloon-compression technique containing 20 micro...

We introduce LZ-End, a new member of the Lempel-Ziv family of text compressors, which achieves compression ratios close to those of LZ77 but performs much faster at extracting arbitrary text substrings. We then build the first self-index based on LZ77 (or LZ-End) compression, which in addition to text extraction offers fast indexed searches on the compressed text. This self-index is particularl...

In this paper a novel approach to the compression of sparse histogram images is proposed. First, we define a sparsity index which gives hints on the relationship between the mathematical concept of matrix sparsity and the visual information of pixel distribution. We use this index to better understand the scope of our approach and its preferred field of applicability, and to evaluate the perfor...

Color vector quantization (VQ) has been an efficient still image compression scheme as well as a popular bihnap graphics format for display devices with limited color capability. In this paper we are proposing a color vector quantization-based video coder, exploiting the temporal stationaty nature of color distribution among a group of pictures (GOP) over a short period. Color VQ is applied fir...

Methods All CMR studies performed for clinical evaluation of pediatric pectus excavatum at our institution were retrospectively reviewed. CMR analysis included evaluation of Haller index, left ventricular (LV) and RV ejection fractions (EF), and indexed LV and RV end-diastolic and end-systolic volumes. The site of maximal compression of the right ventricle (no compression, atrioventricular (AV)...

geometric and material nonlinear behavior of slender webs in i-column girders having stocky flanges under the action of combined lateral and axial loads is investigated. interaction curves corresponding to the application of compressive and shear loads at buckling and ultimate stages for both web plates and column sections are plotted. in addition, the effects of flange and web slenderness rati...

A major problem in surveillance systems is the storage requirements for video archival; videos are recorded continuously for long periods of time, resulting in large amounts of data. Therefore, it is essential to apply efficient compression techniques. Additionally, it is useful to be able to index the archived videos based on events. In general, such events are defined by the interaction among...

For compression of text databases, semi-static word-based methods provide good performance in terms of both speed and disk space, but two problems arise. First, the memory requirements for the compression model during decoding can be unacceptably high. Second, the need to handle document insertions means that the collection must be periodically recompressed, if compression efficiency is to be m...

This paper describes architecture of DCT and DWT standard of an image compression. It is used specially for the compression of images where tolerable degradation is required. The discrete cosine transform is a fast transform and has fixed basis images which gives good compromise between information packing ability and computational complexity. DWT can be used to reduce the image size without lo...