Target classification using SIFT sequence scale invariants

On the basis of scale invariant feature transform（SIFT） descriptors,a novel kind of local invariants based on SIFT sequence scale（SIFT-SS） is proposed and applied to target classification.First of all,the merits of using an SIFT algorithm for target classification are discussed.Secondly,the scales of SIFT descriptors are sorted by descending as SIFT-SS,which is sent to a support vector machine（SVM） with radial based function（RBF） kernel in order to train SVM classifier,which will be used for achieving target classification.Experimental results indicate that the SIFT-SS algorithm is efficient for target classification and can obtain a higher recognition rate than affine moment invariants（AMI） and multi-scale auto-convolution（MSA） in some complex situations,such as the situation with the existence of noises and occlusions.Moreover,the computational time of SIFT-SS is shorter than MSA and longer than AMI.

Scale characters analysis for gully structure in the watersheds of loess landforms based on digital elevation models

Scale is the basic attribute for expressing anddescribing spatial entity and phenomena. It offerstheoretical significance in the study of gully structureinformation, variable characteristics of watershed mor-phology, and development evolution at different scales.This research selected five different areas in China＇s LoessPlateau as the experimental region and used DEM data atdifferent scales as the experimental data. First, the changerule of the characteristic parameters of the data at differentscales was analyzed. The watershed structure informationdid not change along with a change in the data scale. Thiscondition was proven by selecting indices of gullybifurcation ratio and fractal dimension as characteristicparameters of watershed structure information. Then, thechange rule of the characteristic parameters of gullystructure with different analysis scales was analyzed bysetting the scale sequence of analysis at the extractiongully. The gully structure of the watershed changed withvariations in the analysis scale, and the change rule wasobvious when the gully level changed. Finally, the changerule of the characteristic parameters of the gully structure atdifferent areas was analyzed. The gully fractal dimensionshowed a significant numerical difference in differentareas, whereas the variation of the gully branch ratio wassmall. The change rule indicated that the developmentdegree of the gully obviously varied in different regions,but the morphological structure was basically similar.

The Spectrum Sequences of Periodic Frame Multiresolution Analysis

The periodic multiresolution analysis （PMRA） and the periodic frame multiresolution analysis （PFMRA） provide a general recipe for the construction of periodic wavelets and periodic wavelet frames, respectively. This paper addresses PFMRAs by the introduction of the notion of spectrum sequence. In terms of spectrum sequences, the scaling function sequences generating a normalized PFMRA are characterized; a characterization of the spectrum sequences of PFMRAs is obtained, which provides a method to construct PFMRAs since its proof is constructive; a necessary and sufficient condition for a PFMRA to admit a single wavelet frame sequence is obtained; a necessary and sufficient condition for a PFMRA to be contained in a given PMRA is also obtained. What is more, it is proved that an arbitrary PFMRA must be contained in some PMRA. In the meanwhile, some examples are provided to illustrate the general theory.

Novel approaches to the multiscalar display of vector data

There are many challenges to achieving quality multiscalar displays of vector data in geographical information system(GIS).Acknowledging and making use of the differences between traditional cartographic generalization and multiscalar display in GIS,this paper focuses on novel approaches to the definition of small objects and the establishment of scale sequence.The ease of implementation and efficacy of the solutions proposed are exemplified and analyzed.Possibilities for further research into the multiscalar display of vector data in GIS are thereby suggested.

Characterization of Periodic Multiresolution Analysis and an Application

In this paper, we study the properties of periodic multiresolution analysis, and present a complete characterization of the scaling function sequence, which enables us to construct a new scaling function sequence from a given one. An application of the main results is given at the end.