Results 1 - 10
of
11
Trends of Tree-Based, Set-Partitioning Compression Techniques in Still and Moving Image Systems
- IN STILL AND MOVING IMAGE SYSTEMS,” PROCEEDINGS PICTURE CODING SYMPOSIUM 2001, APR., 2001
, 2001
"... In addition to high compression efficiency, future still and moving image coding systems will require many other features. They include fidelity and resolution scalability, region of interest enhancement, random access decoding, resilience to errors due to channel noise or packet loss, fast encoding ..."
Abstract
-
Cited by 14 (6 self)
- Add to MetaCart
In addition to high compression efficiency, future still and moving image coding systems will require many other features. They include fidelity and resolution scalability, region of interest enhancement, random access decoding, resilience to errors due to channel noise or packet loss, fast encoding and/or decoding speed, and low computational and hardware complexity. Moreover, there are emerging new venues for the application of image compression techniques to data associated with points of a two or three-dimensional grid that will demand these features and perhaps others. We shall discuss these new venues along with the usual ones and show how tree-based, set-partitioning wavelet coding methods, such as SPIHT (Set Partitioning in Hierarchical Trees) and SPECK (Set Partitioning Embedded bloCK) will fulfill most of the demands of current and future applications. We shall also discuss the emerging JPEG-2000 in this framework.
IEEE,”Evaluation of JPEG-LS, the New Lossless and Controlled-Lossy Still Image Compression Standard, for Compression of Hi gh-Resolution Elevation Data
- IEEE Transactions on Geoscience and Remote sensing
, 2001
"... Abstract—The compression of elevation data is studied in this paper. The performance of JPEG-LS, the new international ISO/ITU standard for lossless and near-lossless (controlled-lossy) still-image compression, is investigated both for data from the USGS digital elevation model (DEM) database and th ..."
Abstract
-
Cited by 10 (3 self)
- Add to MetaCart
(Show Context)
Abstract—The compression of elevation data is studied in this paper. The performance of JPEG-LS, the new international ISO/ITU standard for lossless and near-lossless (controlled-lossy) still-image compression, is investigated both for data from the USGS digital elevation model (DEM) database and the navy-pro-vided digital terrain model (DTM) data. Using JPEG-LS has the advantage of working with a standard algorithm. Moreover, in contrast with algorithms like the popular JPEG-lossy standard, this algorithm permits the completely lossless compression of the data as well as a controlled lossy mode where a sharp upper bound on the elevation error is selected by the user. All these are achieved at a very low computational complexity. In addition to these algorithmic advantages, we show that JPEG-LS achieves significantly better compression results than those obtained with other (nonstandard) algorithms previously investigated for the compression of elevation data. The results here reported suggest that JPEG-LS can immediately be adopted for the compression of elevation data for a number of applications. Index Terms—Compression, elevation data, JPEG-LS, standard. I.
Smugglers and border guards: the geostar project at rpi
- Proc. ACM-GIS, 2007
"... We present the GeoStar project at RPI, which researches various terrain (i.e., elevation) representations and opera-tions thereon. This work is motivated by the large amounts of hi-res data now available. The purpose of each repre-sentation is to lossily compress terrain while maintaining important ..."
Abstract
-
Cited by 6 (3 self)
- Add to MetaCart
(Show Context)
We present the GeoStar project at RPI, which researches various terrain (i.e., elevation) representations and opera-tions thereon. This work is motivated by the large amounts of hi-res data now available. The purpose of each repre-sentation is to lossily compress terrain while maintaining important properties. Our ODETLAP representation gen-eralizes a Laplacian partial differential equation by using two inconsistent equations for each known point in the grid, as well as one equation for each unknown point. The surface is reconstructed from a carefully-chosen small set of known points. Our second representation segments the terrain into a set of regions, each of which is simply described. Our third representation has the most long term potential: scooping, which forms the terrain by emulating surface water erosion. Siting hundreds of observers, such as border guards, so that their viewsheds jointly cover the maximum terrain is our first operation. This process allows both observer and target to be above the local terrain, and the observer to have a finite radius of interest. Planning a path so that a smuggler may get from point A to point B while maximally avoiding the border guards is our second operation. The path metric includes path length, distance traveled uphill, and amount of time visible to a guard. The quality of our representations is determined, not only by their RMS elevation error, but by how accurately they support these operations.
Multiple observer siting on terrain with intervisibility or lo-res data
- In XXth Congress, International Society for Photogrammetry and Remote Sensing
, 2004
"... We describe two current projects with our toolkit for siting multiple observers on terrain. (Both observers and targets are at some specified height above ground level. Observers can see targets, when not hidden by the terrain, out to a specified radius of interest.) Siting the observers so that the ..."
Abstract
-
Cited by 5 (1 self)
- Add to MetaCart
(Show Context)
We describe two current projects with our toolkit for siting multiple observers on terrain. (Both observers and targets are at some specified height above ground level. Observers can see targets, when not hidden by the terrain, out to a specified radius of interest.) Siting the observers so that they are intervisible, i.e., so that the visibility graph is a connected set, is the first project. The second project tests the effect, on the optimality of the multiple observer siting (w/o intervisiblity), of reducing the map cell’s horizontal or vertical resolution. We lowered the resolution, sited observers optimally, then computed those observers ’ joint visibility index on the hi-res data. We observed that much less precise vertical resolution is ok, but that reducing the horizontal resolution by even a factor of two leads to an observer siting with significantly reduced joint visibility index, when evaluated on the hi-res data. Applications of multiple observer siting include siting radio towers and mitigating visual nuisances. 1
MORSE DESCRIPTION AND MORPHOLOGICAL ENCODING OF CONTINUOUS DATA
"... A geometric representation for images is studied in this work. This is based on two complementary geometric structures for the topographic representation of an image. The first one computes a description of the Morse structure, while the second one computes a simplified version of drainage structure ..."
Abstract
-
Cited by 2 (1 self)
- Add to MetaCart
(Show Context)
A geometric representation for images is studied in this work. This is based on two complementary geometric structures for the topographic representation of an image. The first one computes a description of the Morse structure, while the second one computes a simplified version of drainage structures. The topographic significance of the Morse and drainage structures of Digital Elevation Maps (DEM) suggests that they can been used as the basis of an efficient encoding scheme. As an application we then combine this geometric representation with a consistent interpolation algorithm and lossless data compression schemes to develop an efficient compression algorithm for DEM. This coding scheme controls the L ∞ error in the decoded elevation map, a property that is necessary for the majority of applications dealing with DEM. We present the underlying theory and some compression results for standard DEM data.
Algorithms on triangulated terrains
- In Proceedings of the 24th SOFSEM
, 1997
"... Abstract. Digital elevation models can represent many types of geographic data. One of the common digital elevation models is the triangulated irregular network (also called TIN, or polyhedral terrain, or triangulated terrain). We discuss ways to represent a TIN in a data structure, and give some of ..."
Abstract
-
Cited by 1 (0 self)
- Add to MetaCart
Abstract. Digital elevation models can represent many types of geographic data. One of the common digital elevation models is the triangulated irregular network (also called TIN, or polyhedral terrain, or triangulated terrain). We discuss ways to represent a TIN in a data structure, and give some of the basic algorithms that work on TINs. These include retrieving contour lines, computing perspective views, and constructing TINs from other digital elevation data. We also give a recent method to compress and decompress a TIN for storage and transmission purposes. 1
Session / Séance 51-C Terrain Elevation Data Structure Operations
"... We describe several programs working with 1201x1201 gridded (array) terrain elevation data: determining the viewshed of an observer, and the visibility indices of all points, converting from a grid to a TIN, losslessly and lossily compressing a grid, and interpolating from contours to a grid. The in ..."
Abstract
- Add to MetaCart
We describe several programs working with 1201x1201 gridded (array) terrain elevation data: determining the viewshed of an observer, and the visibility indices of all points, converting from a grid to a TIN, losslessly and lossily compressing a grid, and interpolating from contours to a grid. The intent is to integrate these, and new, programs, into a test suite the better to understand hypsography.
Abstract Image Compression Terrain Simplification
"... We suggest a new terrain simplification algorithm which is based on known Digital Image Processing compression methods (e.g. DCT, wavelets compression) that was specially adjusted to fit Digital Elevation Models. DEM-images are terrains or elevation maps represented as gray scale images. We investig ..."
Abstract
- Add to MetaCart
(Show Context)
We suggest a new terrain simplification algorithm which is based on known Digital Image Processing compression methods (e.g. DCT, wavelets compression) that was specially adjusted to fit Digital Elevation Models. DEM-images are terrains or elevation maps represented as gray scale images. We investigate the special nature of such terrain-images and design a unique pre-compression process which defines the parameters to guide the image compression. We perform a largescale experiment comparing several terrain simplification methods and conclude that the new suggested terrain simplification algorithm (named ICT S) leads to significantly better compression results, faster runtime, and most importantly, for a given file size it represents the original terrain better than other terrain simplification methods. 1
Morse and Drainage Description and Encoding of Images
, 2002
"... In this paper we develop and analyze basic geometric structures for the topographic representation of images. One component of the geometric description is based on the Morse structure of the image, while a second one is connected to its drainage structure. These fundamental descriptors could be use ..."
Abstract
- Add to MetaCart
(Show Context)
In this paper we develop and analyze basic geometric structures for the topographic representation of images. One component of the geometric description is based on the Morse structure of the image, while a second one is connected to its drainage structure. These fundamental descriptors could be used as building blocks for a geometric multiscale representation of images in general and Digital Elevation Models (DEM) in particular. The topographic significance of the Morse and drainage structures of DEMs suggests that they can be used as the basis of an efficient encoding scheme. Therefore, we combine this geometric representation with partial differential equations based interpolation algorithms and lossless data compression techniques to develop a compression scheme for DEM. This algorithm permits to obtain compression results while controlling the maximum error in the decoded elevation map, a property that is necessary for the majority of applications dealing with DEM. We present the underlying theory and compression results for standard DEM data.
GeoSpatial Terrain: Algorithms and Representations
"... Geospatial terrain elevation contains long-range, nonlinear relationships, such as drainage networks. ..."
Abstract
- Add to MetaCart
Geospatial terrain elevation contains long-range, nonlinear relationships, such as drainage networks.
