Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Research Article Three-Dimensional SPIHT Coding of Volume Images with Random Access and Resolution Scalability | Hindawi Publishing Corporation EURASIP Journal on Image and Video Processing Volume 2008 Article ID 248905 13 pages doi 2008 248905 Research Article Three-Dimensional SPIHT Coding of Volume Images with Random Access and Resolution Scalability Emmanuel Christophe1 2 and William A. Pearlman3 1 Tesa IRIT 14 port St Etienne 31500 Toulouse France 2CNES DCT SI AP 18 Avenue E. Belin 31401 Toulouse France 3Electrical Computer and Systems Engineering Department Rensselaer Polytechnic Institute Troy NY 12180-3590 USA Correspondence should be addressed to Emmanuel Christophe Received 11 September 2007 Revised 17 January 2008 Accepted 26 March 2008 Recommended by James Fowler End users of large volume image datasets are often interested only in certain features that can be identified as quickly as possible. For hyperspectral data these features could reside only in certain ranges of spectral bands and certain spatial areas of the target. The same holds true for volume medical images for a certain volume region of the subject s anatomy. High spatial resolution may be the ultimate requirement but in many cases a lower resolution would suffice especially when rapid acquisition and browsing are essential. This paper presents a major extension of the 3D-SPIHT set partitioning in hierarchical trees image compression algorithm that enables random access decoding of any specified region of the image volume at a given spatial resolution and given bit rate from a single codestream. Final spatial and spectral or axial resolutions are chosen independently. Because the image wavelet transform is encoded in tree blocks and the bit rates of these tree blocks are minimized through a rate-distortion optimization procedure the various resolutions and qualities of the images can be extracted while reading a minimum amount of bits from the coded data. The attributes and efficiency of this 3D-SPIHT extension are demonstrated for several medical and hyperspectral
