4 research outputs found
High ratio wavelet video compression through real-time rate-distortion estimation.
Thesis (M.Sc.Eng.)-University of Natal, Durban, 2003.The success of the wavelet transform in the compression of still images has prompted an
expanding effort to exercise this transform in the compression of video. Most existing video
compression methods incorporate techniques from still image compression, such techniques
being abundant, well defined and successful. This dissertation commences with a thorough
review and comparison of wavelet still image compression techniques. Thereafter an
examination of wavelet video compression techniques is presented. Currently, the most
effective video compression system is the DCT based framework, thus a comparison between
these and the wavelet techniques is also given.
Based on this review, this dissertation then presents a new, low-complexity, wavelet video
compression scheme. Noting from a complexity study that the generation of temporally
decorrelated, residual frames represents a significant computational burden, this scheme uses
the simplest such technique; difference frames. In the case of local motion, these difference
frames exhibit strong spatial clustering of significant coefficients. A simple spatial syntax is
created by splitting the difference frame into tiles. Advantage of the spatial clustering may then
be taken by adaptive bit allocation between the tiles. This is the central idea of the method.
In order to minimize the total distortion of the frame, the scheme uses the new p-domain rate-distortion
estimation scheme with global numerical optimization to predict the optimal
distribution of bits between tiles. Thereafter each tile is independently wavelet transformed and
compressed using the SPIHT technique.
Throughout the design process computational efficiency was the design imperative, thus leading
to a real-time, software only, video compression scheme. The scheme is finally compared to
both the current video compression standards and the leading wavelet schemes from the
literature in terms of computational complexity visual quality. It is found that for local motion
scenes the proposed algorithm executes approximately an order of magnitude faster than these
methods, and presents output of similar quality. This algorithm is found to be suitable for
implementation in mobile and embedded devices due to its moderate memory and
computational requirements
Combined Industry, Space and Earth Science Data Compression Workshop
The sixth annual Space and Earth Science Data Compression Workshop and the third annual Data Compression Industry Workshop were held as a single combined workshop. The workshop was held April 4, 1996 in Snowbird, Utah in conjunction with the 1996 IEEE Data Compression Conference, which was held at the same location March 31 - April 3, 1996. The Space and Earth Science Data Compression sessions seek to explore opportunities for data compression to enhance the collection, analysis, and retrieval of space and earth science data. Of particular interest is data compression research that is integrated into, or has the potential to be integrated into, a particular space or earth science data information system. Preference is given to data compression research that takes into account the scien- tist's data requirements, and the constraints imposed by the data collection, transmission, distribution and archival systems
The 1992 4th NASA SERC Symposium on VLSI Design
Papers from the fourth annual NASA Symposium on VLSI Design, co-sponsored by the IEEE, are presented. Each year this symposium is organized by the NASA Space Engineering Research Center (SERC) at the University of Idaho and is held in conjunction with a quarterly meeting of the NASA Data System Technology Working Group (DSTWG). One task of the DSTWG is to develop new electronic technologies that will meet next generation electronic data system needs. The symposium provides insights into developments in VLSI and digital systems which can be used to increase data systems performance. The NASA SERC is proud to offer, at its fourth symposium on VLSI design, presentations by an outstanding set of individuals from national laboratories, the electronics industry, and universities. These speakers share insights into next generation advances that will serve as a basis for future VLSI design