PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.
This PDF file contains the front matter associated with SPIE Proceedings Volume 6751, including the Title Page, Copyright information, Table of Contents, Introduction, and the Conference Committee listing.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
Multi-resolution representation plays leading roles in virtual geographic environment (VGE), interactive simulation and
visualization, fly simulation etc. This paper presents an efficient implementation of adaptive view-dependent and
topology preserving algorithm with which progressive meshes can be selectively refined or coarsened. In contrast to
view-independent algorithms, it allows several different levels of detail to co-exist across different regions of the same
object. Regions with great visual importance are represented with high resolution, other parts are represented with lower
resolution, and so sizes of LOD models generated with the algorithm presented in this paper are much smaller. In the
real-time generation of view-dependent LOD models and its update, parameters such as view point, view frustum,
normal of vertices, and position of vertices are all considered.
The algorithm mainly consists of two phases: pre-processing and real-time update. In the preprocessing phase, an
algorithm based on quadric error metric and edge collapse operator is employed to simplify the original model, and so
the original high resolution model can be represented with a coarse base model and a sequence of edge collapse records,
which we also call progressive mesh representation. In the real-time update phase, progressive meshes are selectively
refined or coarsened according to their visual importance. It is believed that regions fulfill the following two conditions
simultaneously are of great importance: (1) intersection of normal cones and view frustum are non-empty; (2) the
affecting area of a certain candidate vertex joins current view frustum, and so they will be represented with a high
resolution, otherwise, they will be represented with a relative lower resolution.
In contrast, the following two characteristics are different from others: (1) Binary trees are stored implicitly in the edge
collapse records, so spending on memories is less, most important of all, depth of binary trees constructed in this paper is
at least one less than previous algorithms, therefore, traversing of them is faster. (2) Due to the special edge collapse
operator employed in the pre-processing phase, precondition for vertex split operations are more relaxed, and so it is easy
to get simplified models with fewer amounts of data under the condition of same visual effects.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
Different geographical phenomena and processes take on diverse laws, this is to say, specific laws of geographical
phenomena and processes should be researched on a given spatial scale. In addition, geographical phenomena and
processes don't linearly change with spatial scale, which can't obtain by linear interpolation or extrapolation. As a result,
we must resolve the problem of multi-scale representation of geographical spatial data, which is also the key technique
of Multi-Scale GIS or Scale-Free GIS.
At the present time people have to adopt multi-ply representation for the sake of satisfying people's research and
production needs on different spatial scales. However, this method has such shortcomings as a good many data
redundancies, ensuring no the consistency of the same spatial entity on different spatial scales, low efficiency of
updating spatial database and bad real-time characteristic of spatial database. Ideal aim of multi-scale representation of
geographical spatial data is deriving desired spatial database of various scales or detail degrees from dominant
cartographic database, which is automatic generalization of geographical spatial data. Research fields of automatic
generalization of geographical spatial data include theory foundation, concept framework, solution and algorithms of
automatic generalization. Therein algorithms of automatic generalization are the technique basis of automatic
generalization of geographical spatial data.
Since the seventies of the last century people have already put continuously forward a large number of algorithms of
automatic generalization. Those algorithms have indeed resolved a good many important problems, but they have some
obvious shortcomings and application confines. This article makes a research on those algorithms of automatic
generalization, and research contents comprise classification, principle, application confines, merits and drawbacks of
algorithms of automatic generalization. This paper also brings forward the research orientation of algorithms of
automatic generalization for the future.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
There are so many emergency issues in our daily life. Such as typhoons, tsunamis, earthquake, fires, floods, epidemics,
etc. These emergencies made people lose their lives and their belongings. Every day, every hour, even every minute
people probably face the emergency, so how to handle it and how to decrease its hurt are the matters people care most. If
we can map it exactly before or after the emergencies; it will be helpful to the emergency researchers and people who
live in the emergency place. So , through the emergency map, before emergency is occurring we can predict the situation,
such as when and where the emergency will be happen; where people can refuge, etc. After disaster, we can also easily
assess the lost, discuss the cause and make the lost less. The primary effect of mapping is offering information to the
people who care about the emergency and the researcher who want to study it. Mapping allows the viewers to get a
spatial sense of hazard. It can also provide the clues to study the relationship of the phenomenon in emergency. Color, as
the basic element of the map, it can simplify and clarify the phenomenon. Color can also affects the general
perceptibility of the map, and elicits subjective reactions to the map. It is to say, structure, readability, and the reader's
psychological reactions can be affected by the use of color.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
Grid-city management currently attracts a wider audience globally. Socio-economic data is an essential part of grid-city
management system. Social-economic data of an urban is characterized by discrete, time-varying, statistical, distributed
and complicated. Most of data are with no exactly spatial location or from various statistical units. There is obvious gap
while matching social-economic data with existing grid map of natural geographical elements emerges. It may cause
many difficulties in data input, organization, processing and analysis while the grid system constructing and executing.
The issue of how to allocate and integrate the huge social-economic data into each grid effectively is crucial for grid-city
construction. In this paper, we discussed the characteristics of social-economic data in a grid-city systematically,
thereafter a cell-based model for social-economic data representing and analyzing is presented in this paper. The kernel
issues of the cell-based model establishment include cell size determining, cell capabilities developing for multi-dimension
representation and evaluation, and cell dynamic simulation functions designing. The cell-based model
supplements the methods system of spatial data mining, and is also promising in application to the spatialization of
statistical data obtained from other researches including environmental monitoring, hydrological and meteorological
observation.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
The history of editing National Atlases in the world was summarized at first, and follows with China's achievements in
editing of the 1st and 2nd version of The National Atlases of China (NAC), which reflected, in multiple levels, China's
development of science and technology, society and economy, resources and environment, etc. from 1950s to 1980s. From
the previous edition of NAC, systematic theories and methods were summarized and concluded, including
comprehensive and statistical mapping theory, designing principle of electronic atlases, and new method the technologies
involved in NAC. Then, the New Century Edition of NAC is designed, including its orientation, technological system,
volume arrangement, and key scientific and technological problems to be resolved.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
3D Laser scanning technology plays an important role in buildings model reconstruction, mechanical modeling, heritage
conservation, tunnels modeling, bridges and mine monitoring, etc. This technology can acquire accurate and dense 3D
points cloud data in a short time, and it's becoming an important data acquisition means of 3D model. The construction
of high-quality 3D triangulated irregular network (TIN) using the irregular points cloud is one of the key problems in
model reconstruction. However, the 3D triangulation of discrete points cloud is a difficult problem and contains very
complex principle, until now, the problem has not been satisfied resolved. In this paper, a 3D Delaunay triangulations
algorithm of terrestrial laser scanning data based on spherical project is proposed. In the algorithm, the connection
characteristics of the 3D laser scanning data are deeply investigated and utilized to help judge the relation of irregular
points.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
This paper explores an approach for predicting land cover types of central Montana, USA based on satellite measurement
and digital terrain data. We assume a non-linear inherent relationship existing between land cover types and Landsat TM
reflectance and terrain variables. To measure this relationship we use Generalize Linear Models (GLMs), which are
mathematical extensions of ordinary least-square regression models. Specifically, stepwise logistic regression technique
is applied to optimize the predictive model. For the analysis of the significance of dropping or adding terms, the Akaike
information criterion (AIC) is used. Likelihood Ratio Test (LRT) is applied to test the validity of explanative potential of
predictor variables. We use cross-validation method to evaluate the predicative accuracy of land cover mapping using
GLMs. Finally we table the relative risk ratios of GLMs. Since relative risk ratios explicitly represent the explanative
efficiency of predictor variables, their ranking can pick up the variables with significant explanatory potential in
discriminating land cover types, which will be significative for simplifying the predictive models. It is anticipated that
GLMs will be valuable extension to semi-automatic classification of remotely sensed imagery, and an effective tool for
land cover mapping.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
It is a delicate task to design suitable geovisualisations that allow users an efficient visual processing of geographic
information. In digital era, such a design task is confronted with a three-fold challenge: the ever growing amount of
geospatial data at various granularity levels, the diversified applications and the continuously expanding range of display
sizes. A geovisualisation system that strives for a high usability must satisfy the crucial prerequisite of immediately
directing the user's gaze to the location of relevant geographic information and of easy decidability of the underlying
semantic meanings. To this end, the cognitive skill of visual attention contributes to mnemonic and executive processes.
Attention is indispensable for the visual selection. It facilitates the relevant information retrieval, processing and storage.
On the basis of neurocognitive visual information processing, the paper addresses the interdisciplinary approach of
attention-guiding design of geovisualisations with the intention to establish a taxonomy of scientifically testable
variables. The authors try to relate attention-guiding attributes with graphical variables that cartographers apply to
encode geographic information. The work is driven by the motivation to enhance the efficiency of geovisualisations and
to enable a more precise neurocognition-based evaluation of geovisualisations.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
In contrast to traditional cartography, schematic network map including road and river network needs new cartographical
generalization methods. In this paper, the cartographic design criteria of schematic road network map are analyzed and
summarized. Based on this, a set of quantitive constrains are set up, and a new road network generalization method
including progressive selection and displacement is proposed. Furthermore, we research topological checking method for
road network. Based on these constrains, the points in a road network are classified, and a satisfied and effective
schematic map is designed in a concrete experiment, while keeping the topological consistency of the road network
between original and schematic map.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
Delaunay triangulation is always used to construct TIN, and is also widely applied in manifold fields, for it can avoid
long and skinny triangles resulting in a nice looking map. A wide variety of algorithms have been proposed to construct
delaunay triangulation, such as divide-and-conquer, incremental insertion, trangulation growth, and so on. The
compound algorithm is also researched to construct delaunay triangulation, and prevalently it is mainly based on divide-and-conquer and incremental insertion algorithms. This paper simply reviews and assesses sweepline and divide-and-conquer
algorithms, based on which a new compound algorithm is provided after studying the sweepline algorithm
seriously. To start with, this new compound algorithm divides a set of points into several grid tiles with different
dividing methods by divide-and-conquer algorithm, and then constructs subnet in each grid tile by sweepline algorithm.
Finally these subnets are recursively merged into a whole delaunay triangulation with a simplified efficient LOP
algorithm. Because topological structure is important to temporal and spatial efficiency of this algorithm, we only store
data about vertex and triangle, thus edge is impliedly expressed by two adjacent triangles. In order to fit two subnets
merging better, we optimize some data structure of sweepline algorithm. For instance, frontline and baseline of
triangulation are integrated into one line, and four pointers point to where maximum and minimum of x axis and y axis
are in this outline. The test shows that this new compound algorithm has better efficiency, stability and robustness than
divide-and-conquer and sweepline algorithms. Especially if we find the right dividing method reply to different
circumstance,its superiority is remarkable.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
Object selection is an important technical problem in the process of map generalization. Considering creative-thinking
characteristic of map generalization process, the paper bring the Rough Set theory from spatial data mine field to map
generalization field, put forward a new thought for map generalization based on classification idea of Rough Set. The
method of Rough Set which has the benefit on enormous data with the imperfection and non-precision character has
become a new tool to make research on spatial data mining. The paper analyzes the imperfection characters of
geo-spatial data processing based on Rough Set and the selection problem in the processing of map generalization with
classification thought; presents the thought that map generalization is a kind of classification for map objects. The
method mentioned in this paper use different spatial and attribute information as different point of view to observe the
map objects. The result of the classification is ordered by the weightiness of all kinds of factors. In the end, a river
objects selection test validates the rough set map generalization method mentioned in this paper.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
In order to reveal and implement the corresponding association about the same geographical feature at different
resolutions and to build the multi-scale spatial database and maintain the consistency between different scale map
databases, an algorithm for matching multi-scale linear objects based on Hausdorff Distance as a matching measure is
proposed combined with the semantic information. Further more, the concept of matching uncertainty is defined as to
evaluate the matching result. The experiment and the estimate result show that according to the characteristics of road
networks changing with scales, this approach can recognize the entity or a set of entities which represent the same object
at different scales so as to build the relationships of corresponding objects.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
This paper proposes a progressive approach to selecting streets from an urban street network. This approach relies on the
constraints in generalization of the street network and the ameliorated dynamic decision tree structure which represents
the map data by a tree. The paper begins with a review of theory and methodology of constraint-based map
generalization, of approaches to generalization of the road network and street network, and of some auxiliary structures
which are useful to represent contextual topological relation. And then a conceptual framework for map generalization is
presented. In the following, the methodology is described under this framework and the ameliorated dynamic decision
tree structure is introduced in detail. An algorithm is developed and the proposed approach is validated by a case study.
The paper concludes with some discussion on the benefits and shortcomings of the approach.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
This paper mainly discusses how to realize the symbolization control of digital maps through symbolization control
knowledge. First, the author briefly introduces basic concepts and means of realizing symbolization control of digital
maps after analyzing the current problems of digital map symbolization. Then the author analyzes the composition of the
symbolization control knowledge, and proposes some important concepts such as the expression of geographic attributes,
the annotation's positional control code and the format string expression. Finally, the author designs and realizes the
symbolization control interface with man-machine interaction. Practice has also proved that it is effective to realize the
symbolization control of digital maps through knowledge of symbolization control.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
Drainage generalization is a process of information abstraction, aiming to derive a coarser dataset from original detailed
one. The difficulties lie in selectively omitting some rivers while maintaining the overall characteristics of the drainages.
This paper took use of the amount of the tributaries of individual rivers to evaluation their relative importance in the
drainage, and the contribution to the preservation of the drainage pattern. That is, the rivers having more tributaries are
more important than those having fewer tributaries; at the same time, the differences of the amount of the tributaries of
the rivers may indicate the density differences of their sub-drainages. In view of the important role of river length and
hierarchical level in manual generalization, we combined river length, hierarchical level and the amount of the tributaries
to evaluate rivers. The three indexes were computed, and then integrated as a complex index for every river, on the basis
of constructing a river tree of the drainage. A case study of drainage generalization shows that the complex index is effective
to reflect the relative importance of the rivers in the drainage, and can be used to maintain the density differences
of the drainage in map generalization.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
The acreage of a land parcel is the area of the parcel's coverage on the geodetic ellipsoid surface. There are two methods
to compute the land parcel acreage from its area in the map projection coordinate system. The first method is to compute
the acreage of an administrative zone, then use the acreage of the administrative zone to control the acreages of the land
parcels within it. The second is to compute the acreage of a map sheet first, and then use the acreage of the map sheet to
control the acreages of the parcels within that map sheet. There are three methods to calculate the slope grade of land
parcels, each has advantages and disadvantages. They should be used under careful consideration of the specific
situation.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
This paper studies the principle, method and application of spatial points clustering based on self-organizing neural
networks. In this paper, we put forward a kind of composite clustering statistic, called generalized Euclidean distance,
which is calculated by both geometric and semantic characters of spatial points. We propose the algorithm of spatial
points clustering based on self-organizing feature map and generalized Euclidean distance. The clustering method in this
paper can generate better result reflecting the clustering characters of spatial points. Finally, we employ a case study to
probe into data classifying, gross error detecting and homogeneous areas partitioning using self-organizing spatial
clustering result.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
Urban Underground Pipeline System has grown up to diversity and complex networks; moreover, they have the
characteristics such as invisibility, magnanimity and continuous variation. It is necessary for accelerating development of
city to establish integrative model of urban pipeline-road-stratum with the techniques of Digital Underground Space and
Engineering (DUSE). The key method of some spatial analysis are presented in the present model, it includes integrative
break surface analysis, horizontal net distance analysis and cross vertical net distance analysis in any of the given
section; especially, DUSE takes out the three dimensional distance analysis or interference judgment between pipelines.
Nowadays, the general method which distinguishes the state of interference in multi-manipulator system simplifies shaft
into line-segments, then calculates the distance between two line-segments or the intersected position without taking the
shape of shaft into consideration. In DUSE, the state of interference in pipelines is computed by Boolean operation; if
two pipelines haven't intersection, a series of algorithms based on the theory of analytic geometry is put forward to
calculate 3D distance between circular pipelines, quadrate pipelines or their combination.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
Earlier research has introduced the concept of discriminant space, which is spanned by the covariates underlying
area-class occurrences, for increased consistency, interpretability, and replicability in area-class mapping and uncertainty
characterization. While simple univariate cases with b=1 (b being the dimension of the discriminant space) were
investigated previously using simulated data, real world applications are usually multivariate with b>1, thus giving rises
to the need for developing discriminant models in spaces of higher dimensionality for increased applicability. This paper
describes combined use of generalized linear modeling and kriging for area-class mapping, with the former
deterministically predicting mean class responses while the latter making use of spatially correlated residuals in the
predictive class models. Scalability in area-class mapping is facilitated by flexible implementation of scale-dependent
prediction of mean class responses and point- vs. area-support kriging of the residuals. This is followed by an empirical
study concerning land cover mapping in central western Montana, which confirmed the effectiveness of the proposed
strategy combining regression and kriging for scale-dependent mapping of area classes.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
A new classification scheme of elevation points is put forth on the basis of the study about different kinds of elevation
sampling points and feature lines used to build Digital Elevation Model (DEM). All the elevation points are divided into
two classes, namely Control Elevation Point (CEP) and General Elevation Point (GEP). GEP is subdivided into two
subclasses, namely, Key Elevation Point (KEP) and Dense Elevation Point (DEP). In order to depict micro-terrain with
fine resolution and high efficiency, especially the micro-terrain in plain, six kinds of elevation points are used to
construct Delaunay Triangulated Irregular Network (D-TIN) successfully in case study. It shows that these elevation
points can be used to represent the complex micro-terrain like isolated hills with fine resolution and high efficiency by
use of traditional D-TIN constructing algorithm and 3D terrain visual algorithm if they are sampled along their
corresponding feature lines and Dense Elevation Points (DEPs) are far enough from any feature lines. The representing
resolution changes along with the number of DEPs. The case study also shows that a new elevation points sampling
strategy is required to ensure the correction of D-TIN and a new visual algorithm to visualize the cliff surface more
smoothly.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
There is some relationship between the Digital Surface Model (DSM) and the Digital Terrain Model (DTM). The
contents they express are relative: DSM expresses the height we focus on about the surface of the ground, including
the terrain and the objects on it, and DTM only gives the height of the terrain excluding the objects above it. DSM
have the information of DTM, therefore it provides us a chance to subtract the DTM from the DSM. Mathematical
morphology is a new method applied to Imagery processing and pattern recognition fields. It provides an effective
method of subtracting DTM from DSM. But in practical application, the original calculations of these two are in low
efficiency. Especially when it comes to a large template or huge block data, the computation speed can be a very
headache question. This paper is studying the implementing process of the Open and the Close operators, especially
the Erode and the Dilate calculations. Then we have developed two kinds of quick algorithms, which are aim to
avoid the repeated calculation, and to enhance the efficiency sharply. The step of the two operations also should
be refined, while the disposals are different from each other depending on the distinct configuration of these two
kinds of algorithms.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
Digital cartography provides lots of geographic data for our society, although the traditional technology of cartography is
very complex and tortuous. Also its long produce-cycle affects the effort of maps. Based on introduction of Model-Driven theory, this article shows a construction of automated framework of task-flow, and gives the methods for building
the key components. At last, an example of data exchanging is provided to validate the feasibility of automated
framework theory.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
For monitoring or tracking a vehicle locally or remotely, positioning information should be stored locally or transferred
through wireless network timely. One of those key problems in such a system is to find an appropriate time-duration to
update the position of the vehicle. If the time-duration is too small, too much positioning data will be stored locally or be
transferred; but if the time duration is too big, the track cannot be recorded faithfully, and you can not identify the actual
route the vehicle just went through. To resolve this problem, an adaptive method based on map-matching technology and
fuzzy description is presented in this paper. Through running map-matching by comparing the vehicle's positioning
information with road network geometrical and topological information in digital maps, a more precise position can be
obtained and the current road can be identified. After that, the following factors are considered to detect whether the
current position need be updated in center control unit: time duration, running distance, estimation error, the vehicle state
changing, and running road changing. A deduction method is used to estimate and compare with the measured vehicle
state. And a quantitative fuzzy description is used to describe the speed and angular speed of the vehicle. After that, an
OR arithmetic logic computing unit is used to decide whether need update current position to center control unit. Finally,
a test is given to evaluate this algorithm. The proposed adaptive algorithm can record the vehicle's track faithfully, and
at the same time it decreases the communication cost between the mobile station and the center control unit.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
Cartographic visualization represents geographic information with a map form, which enables us retrieve useful
geospatial information. In digital environment, cartographic symbol library is the base of cartographic visualization and
is an essential component of Geographic Information System as well. Existing cartographic symbol libraries have two
flaws. One is the display quality and the other one is relations adjusting. Statistic data presented in this paper indicate
that the aliasing problem is a major factor on the symbol display quality on graphic display devices. So, effective graphic
anti-aliasing methods based on a new anti-aliasing algorithm are presented and encapsulated in an anti-aliasing graphic
library with the form of Component Object Model. Furthermore, cartographic visualization should represent feature
relation in the way of correctly adjusting symbol relations besides displaying an individual feature. But current
cartographic symbol libraries don't have this capability. This paper creates a cartographic symbol design model to
implement symbol relations adjusting. Consequently the cartographic symbol library based on this design model can
provide cartographic visualization with relations adjusting capability. The anti-aliasing graphic library and the
cartographic symbol library are sampled and the results prove that the two libraries both have better efficiency and effect.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
The Regional Geological Mapping (RGMAP) System developed by China Geological Survey Bureau is a GIS system for
digital geological mapping, which has made a great change to traditional geological survey. RGMAP is composed of two
parts: Digital Route System and Digital Section System. Each of them contains two subsystems, namely, the
Palm-PC-Based Field Data Capture System and the In-house Desktop System. We discuss mainly the Digital Section
System in this paper. In the field, we have achieved the section measuring digitally in computer by means of using the
Palm-PC-Based Field Data Capture System. The Digital Section System (In-house Desktop Subsystem) can
automatically calculate the thickness bed by bed, as well as create the Measured Section Chart and Columnar Chart,
which has dramatically enhanced the measurement of geological section and its cartographical techniques.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
Normally, agricultural land parcels being close to town centers and connected with road systems have higher probability
to be converted for newly planned settlements because these land parcels have higher accessibility influenced mainly by
the transportation condition. A comprehensive method is proposed to simulate the process of allocating land parcels for
the newly planned settlements with the raster data model using some elementary spatial analysis functions provided by
ArcGIS. The first step of the method is to construct the distribution of the cost-distance from each transferable land
parcel to the centers of administrative units at village level (called 'origin' for short). The second step is to simulate the
process to allocate the transferable land parcels for satisfying the land demand resulting from the development at these
'origins'. It is quite possible that more than one origin is interested in the same transferable land parcel. Therefore, how
to determine the priority of different origins to get the land parcel focused by more than one origin is emphatically
discussed as one key point of the proposed method in this paper. In addition, some other aspects, such as the size of the
transferable land parcels, which influences strongly on the results of assignment, are discussed as well. The proposed
method has been applied in the Sino-Germany project 'Sustainable Development by Integrated Land Use Planning' and
can meet the requirements.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
The mutual conversion between analog map and digital map is two main contents of the study on digital mapping, which
is the production of paper map and spatial data. The visualization of spatial data is the common problem that the spatial
data application system confronted, so it is practically meaningful to study the mutual conversion between analog map
and digital map. The paper indicates the two processes of the decrease and increase of cartographic information content
in two conversions, educes a cartographic information transfer model based on Shannon communication system model,
and makes a deep quantitative and qualitative analysis on the decrease and increase of cartographic information in
analog/digital conversion in terms of information theory and cartographic theory. The paper also shows that the accuracy
of cartographic information should be improved in analog-digital conversion and the information content transformed
should be increased to the fullest extent in digital-analog conversion. The corresponding disposal is respectively given
for the two processes.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
Although the production of nautical chart has developed a lot in China, there are still some defects, such as the long
period of producing nautical chart, the continuous correction to the nautical chart published, and so on. On basis of
analyzing Chinese chart publishing data and its updating data, this paper researches on the technique of interactively
updating server chart publishing data and the technique of automatically updating client chart publishing data, which will
lay the foundation for constructing the mode of printing charts on demand in China.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
Web online applications present a lot of challenges for spatial data generalization, in this paper, a novel method of spatial
data generalization for real time visualization is presented. In this method Quadtree Index of Priority (QIP) is used to
control real time data generalization in 3D rendering process. Priorities of points elimination from objects is composed of
contrived priority and automatic priority. Contrived priority is determined by attributes of objects, while automatic
priority is automatically calculated from object's geometry shape by vision-based algorithm and Fast Segmentation (FS)
algorithm. In addition, quadtree index of priorities is also proposed to be used in global data generalization control. In
order to test the generalization method, an experiment with large scale vector data visualization is given.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
According to studying the coastline, a new way of multiple representations is put forward in the paper. That is
stimulating human thinking way when they generalized, building the appropriate math model and describing the
coastline with graphics, extracting all kinds of the coastline shape information. The coastline automatic generalization
will be finished based on the knowledge rules and arithmetic operators. Showing the information of coastline shape by
building the curve Douglas binary tree, it can reveal the shape character of coastline not only microcosmically but also
macroscopically. Extracting the information of coastline concludes the local characteristic point and its orientation, the
curve structure and the topology trait. The curve structure can be divided the single curve and the curve cluster. By
confirming the knowledge rules of the coastline generalization, the generalized scale and its shape parameter, the
coastline automatic generalization model is established finally. The method of the multiple scale representation of
coastline in this paper has some strong points. It is human's thinking mode and can keep the nature character of the curve
prototype. The binary tree structure can control the coastline comparability, avoid the self-intersect phenomenon and
hold the unanimous topology relationship.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
The research introduces skeleton extraction algorithms into cartographic generalization to solve the problem of
cartographic generalization of cultivated land polygons in hilly areas. The study selects southwest region of the
Ningxiang County in the Changsha City as the research area and national land use survey on the scale of 1: 10000 as data
source, chooses an appropriate skeleton extraction algorithm depending on the research purpose and data source, and
propose an improved algorithm applicable for cultivated land in hilly area after a lot of experiments. And then the
improved algorithm is applied to cartographic generalization work of cultivated land in the research area. Results show
that: first, the improved skeleton extraction algorithm is simple, easy and efficient; secondly, under the condition that
scale changes greatly, it could still retain the Figacteristics of cultivated land polygons' distribution and shape and satisfy
the requirements of cartographic generalization and human vision.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
The Meta Fractal Dimension (abbreviated as MFD) Model is a method which extends the fractal research of map objects.
During the establishment of MFD, the size of sliding window determines the neighborhood range which restricts the
segment from the map object and the degree of adjacent overlapped, thus it is one of the most important parameters for
MFD. In present research, however, it is chosen artificially, that causes random and unsatisfied operating efficiency.
Considering the extended fractal character with scaling variance, and based on its simulating function adopting the
Inverse Logistic Model, the paper proposed a method to determine the size of sliding window automatically for
constructing MFD of map curve, viz. MFD curve. Several experiments done indicate that this method is easy to operate
and has a relatively high calculation precision and a logical result of spatial analysis.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
Since decades it has been a dream of cartographers to computationally mimic the generalization processes in human
brains for the derivation of various small-scale target maps or databases from a large-scale source map or database. This
paper addresses in a systematic way the polarization transformation (PT) - a new algorithm that serves both the purpose
of automatic generalization of discrete features and the quality assurance. By means of PT, two dimensional point
clusters or line networks in the Cartesian system can be transformed into a polar coordinate system, which then can be
unfolded as a single spectrum line r = f(α), where r and a stand for the polar radius and the polar angle respectively. After the transformation, the original features will correspond to nodes on the spectrum line delimited between 0° and
360° along the horizontal axis, and between the minimum and maximum polar radius along the vertical axis. Since PT is
a lossless transformation, it allows a straighforward analysis and comparison of the original and generalized distributions,
thus automatic generalization and quality assurance can be down in this way. Examples illustrate that PT algorithm meets with the requirement of generalization of discrete spatial features and is more scientific.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
It is difficult to carry out the automatic cartographic generalization of urban buildings, because of their complex shape.
An algorithm and some constraints for generalization using Least Squares Adjustment theory are presented, with
analyzing the procedure of generalization for urban buildings under multi-scale environment. Automatic generalization
for building polygons can be carried out in the algebra way, with building the automatic generalization adjustment model
including simplification, aggregation, displacement and symbolization. The practice shows that the object shape is
represented perfectly by the algorithm, with providing a basis for evaluation on results of generalization, which improves
the procedure of automatic generalization in scientific and feasibility.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
In this paper, the feature selection rules of patches were regarded as the breakthrough point, based on data analysis and
experiments, the computing method of area balance control of land types was put forward in order to solve the problem
of area changes of every land type before and after synthesis. The computing method of area balance control of land
types can be used not only to check up the rationality of rules before cartographic generalization, but also to provide
assistance advice for revising feature selection rules according to the requirement of the synthesized results. It is helpful
to enhance the rationality and reliability of synthetic rules, to achieve the area balance of various land types before and
after it is synthesized, and to guarantee the quality of the diagram.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
Map objects' displacement is an important operator in the map generalization and spatial information visualization. In this
paper, the constraints of map objects displacement and their satisfaction method with the finite element method are discussed,
in which the constraints of map objects displacement and strategies of parameters of finite element method in the
displacement process play important roles for the displacement result, and compromised with the spatial reasoning method, a
progressive node displacement method is discussed in this paper, which is examined with a road widening case. And the
result shows that the force and the force propagation can be considered comprehensively in this method, through which
unnecessary map object displacement can be avoided.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
In the paper, the main method we discuss and improve relates to the snake model, which is used to displace the roads and
resolve the conflict. A snake is an energy-minimizing spline guided by internal constraint forces and influenced by
external enforcement. In the paper, the theory of snake model is illustrated in detail. Then, according to the demand of
cartography, the snake model is improved as follows. First, the relationship between the parameters of snake and shape
character of road is built up in order to keep the shape of displaced road better. Second, the propagation extent of
external force in snake model is controlled to keep the accuracy of road position. Third, the power attribute of
intersection point between roads is set to control the displacement of the intersection point and keep the topological
relationship of roads. At last, the general thought of disposing the spatial conflict of road networks are brought forward
by using the improved snake model. One experiment research is made in terms of the general thought, which represents
that the roads are displaced and the spatial conflicts are solved well.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
This paper presents a new method of extracting and identifying point-shaped symbols of scanned topographic maps
based on Distance Transformation. First, we remove of the interferences of transition color pixels on symbol edge, and
filter the lines which do not meet the features of point symbols according to curve density and line density, and extract
point symbols from the map based on adding hull transformation and removing skin transformation. Then we judge
topology consistency by skeleton of symbol and shape consistency by weighted distance function, and use the both
consistency to identify symbols. The algorithm can extract and identify rotated or distortional point symbols in the
condition of character and line conglutination or complex background, and the identification accuracy is 98%.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
In the practice of cartography, people always face two kinds of geographic world's models. One is digital landscape
model (DLM), and another is digital cartographic model (DCM). In DLM, geographic feature are expressed by
coordinate, attribute and relationship among them, it is independent from symbols. Reversely, DCM is closely related
with symbols and paper maps which will be published. In this paper I will discuss the design of map database for DCM.
First, this paper introduces characteristics of GIS database and Map database to us, and then elaborates their
relationships and differences.
Second, it represents the contents of map database, which consists of five parts such as spatial location, attributes,
spatial relationship, time, symbol and cartographic expert's knowledge for symbolization control. So we can draw a
conclusion that the map database is an organic combination of GIS database and cartographic expert's knowledge.
Third, this dissertation depicts the implement of map database by an example which is applied in the paper topography
mapmaking and infrastructural geographic information's yield. We design data tables according to geographic feature's
geometry type such as point, line, polygon, complex and annotation. By foreign keys related to dictionary tables we can
divide features into different geography layers (such as vegetation, river, road etc.) and publish layers (such as red point,
black line, green polygon, black annotation etc.). Aiming at different geographic feature possessing of different items of
attributes, we also design a universal method to store feature's attribute data.
Fourth, this dissertation introduces a method using cartographic expert knowledge and experience to control the
process of dynamic map symbolization. The authors think it should formalize the fuzzy and ambiguous expert
knowledge and build expert knowledge repository. By an example it illustrates how to establish cartographic expert
knowledge repository and how the formalized expert knowledge to control the geographic features' symbolization. And
then, it elaborates how the formalized cartographic expert knowledge to controls the annotations' symbolization on a
map.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
Map projections are attempts to portray the surface of the earth or a portion of the earth onto a flat map surface. This can
not be done without any distortions of conformality, distance, direction, scale, and area. There are many map projections,
and each of them has its own set of advantages and disadvantages. The mapmaker must select the one best suited to their
application needs, reducing distortion of the most important features. However, how to select a 'proper' map projection
is a complex process involving general evaluation of map projection alternatives based on a set of characteristics that
describe these projections. And this process needs a systemic understanding of map projection, which usually can not be
achieved by end users. This paper introduced Expert system (ES) to solve this problem, and used Component Objects
Model (COM) technology to develop and interoperate the proposed system (developed with Visual Prolog 7.0 Personal
Edition®) with professional Geographical Information System (GIS) software. As an essential part of the article, the
authors also represented the knowledge, rules and reasoning methods of selecting an appropriate map projection as well.
Implementations and examples had been given to testify the feasibility.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
Geographic Information Systems, especially accurate digital traffic maps, have been becoming widely used in the
Intelligent Transportation Systems. The GPS data usually are more accurate than the pre-existing base map data. This
paper introduces a new cartography procedure for making digital map from a start-up paper map, which has no
geography data (longitude and latitude). Contrary to traditional map-making which is first a precise survey-cartography
and follow-on digital controlled mapping, the new procedure is first extracting layer from a raster map and vectorization,
follow-on geo-adjusting for pinpointing all nodes on the vector map. There are two key processes in the new digital map-making
technique. First, the map layer extraction is controlled by output feedback for optimal recognition of road
network. Second, a dynamic topological mapping is developed for geo-location and improving the accuracy of vector
traffic map by utilizing some recorded GPS data as the controlled pinpoint samples. Different from those traditional geolocation
methods such as affine mapping, and the rubber-streeting with manual point-by-point matching, the new
adjusting is decomposed into a series of optimal topological sub-mapping on relative sub-map region. Based on
pinpointing one sample point to its accuracy location, the sub-mapping adjusts all nodes within the sub-map region.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
This paper argues that electric map is formed to an image on the retina, takes the study of image processing and visual
physiology as reference, and presents a new quantitative measurement of electric map information. Shape, color, texture
and spatial relation are four factors deciding map information. The formula is given also.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
Contour line is a closed curve that joined by points of the same elevation. This paper puts forward a new algorithm of
creating contour line based on DEM, which uses the method of tracking the same elevation point to study the algorithm
based on regular grid. This paper will be divided the algorithm of creating contour line into four sub-algorithms, namely:
the algorithm of elevation comparison, the algorithm of calculating the same elevation point coordinates, the algorithm
of tracking next point of the same elevation, the algorithm of tracking contour line. The algorithm of elevation
comparison is mainly used in judging whether a contour line with appointed elevation passes through a side of the grid;
the algorithm of calculating the same elevation point coordinates is used to calculate coordinates of contour lines across
the grid's side; function of the algorithm of tracking next point of the same elevation is to track next point of the same
elevation by following the trend of contour lines; the algorithm of tracking contour line aims in tracking coordinates of
the point which has the equal value of elevation with the point in row x and column y.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
The daintily and efficiency of electronic atlas visualization are all along the aim of designers and users. But nowadays
most of GIS soft wares adopt GDI mode to display electronic atlas. On account of the localization of GDI, it restricts the
beauty and effect of electronic atlas. As the upgrade of GDI, the function of GDI+ is very powerful. Aim at the
characteristics of GDI+, the writer introduces the application of GDI+ in electronic atlas visualization detailed, includes
advancing of program efficiency, improving of displaying effect and displaying transmutative annotations.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
As an emerging field, cognitive map kept playing a significant role in geography these decades. To date, there are two
dominant methods to externalize human's internal cognitive map, namely, multidimensional scaling (MDS) and skech
mapping. However, among most recent researches on cognitive map, the differences between both methods are always
ignored. The usage of one method over another is still under scrutiny. In order to shed light on the similarity or
distinctions of MDS configuration and sketch mapping, we conducted an experiment on Beijing residents by requesting a
sketch of the region within 3rd Ring and meanwhile extracting distance estimates between 8 landmarks. Employing the
Bidimensional regression along with standard deviational ellipse, we studied the global and local distortions among two
kinds of cognitive maps and quantitatively measure the overall and local cognitive maps distortions. Besides, we use
Monte Carlo simulation method to calculate the radius of distortion for the Distortion Index (DI). It shows that the
average cognitive distortion of habitants in Beijing is 2km to 3km, and the distortion takes 2nd-ring road as a border,
displaying a southwest-northeast diagonal stretch and an east-west contracted tendency. The distortion in the two
methods is remarkably both correlated with factors, such as travel frequency and years of residence. Comparing two
methods, it turned out that sketch map was more consistent with real map, while the distortion orientations of sketch map resembled MDS configuration. Finally, we gave possible reasons with regard to above conclusions and advices for future usage of two methods.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
Map presentation of geographical information based on GIS is an urgent problem lying in current GIS and cartography.
Handling of features' relationship is the key in automatic-mapping. However, the discover and disposal of spatial
conflict is the lowest degree of automation in cartography. A lot of work is still in handwork. After analyzing the data in
the scale of 1:50,000 and 1:250,000, this article summarizes the relationship of cartographic features as
overlapping-relation, attachment-relation and collision-relation. Combined with the data, the article put forward the
method which is related to each of relationship.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
As the development of thematic map design and mapping, the trend of geosciences knowledge and cartographic mapping
knowledge representation is becoming formalized and quantified. This research is aimed to discuss application of
geosciences knowledge and cartographic mapping knowledge in thematic map design, to investigate classification and
representation method of them, and to analyze their practicability and efficiency in thematic mapping intellectualization
design. It could be used as basis for decision making in automatic thematic map design. This research proposed the Thematic Mapping Intellectualization Design Model (TMIDM), which is the key issue for thematic mapping intellectualization. And geosciences knowledge and cartographic mapping knowledge application models for thematic mapping intellectualization design were also discussed.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
Landform feature points and lines have been used as basic landform descriptors of landform skeleton in many fields,
including surveying, simulation of hydrology, landform classification, and vegetation mapping. With the objective of
landform classification from DEMs, an approach has been put forward based on topological parameters and the extended
ones. The methodology for landform classification is implemented as a three-step process: choice of appropriate scale for
analysis, extraction of feature lines, and quantitative measurement of feature lines. Five parameters, entropy of graphs,
edge adjacency index and elevation difference weighted adjacency index, number graphs and density of graphs are used
to classify different landforms. The result shows that topological index and descriptive parameters of graphs, aided by
mean elevation is capable to classify of the high mountain, Loess Mao, Loess Liang and Low mountain.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
Building detection and extraction from digital surface model (DSM) becomes more and more attracted when high
resolution airborn radar and CCD sensor find their more applications in photogrammetric field. Because DSM contains
the terrain heights, we firstly derive DTM from DSM, and then generate Normalized DSM (NDSM). The buildings are
extracted from NDSM. However, since urban appearance is complex, with large buildings, small buildings, trees in mass, etc., building extraction is implemented through several stages. Local Surface Normal Angle Transform (LSNAT) is implemented to the height field. Big buildings are distinguished from other large regions generated from binary NDSM. Watershed segmentation is used to detect trees in mass together with LSNAT. Roofs of the small building are extracted based on the histogram of LSNAT. A case study is presented and analyzed in the end of this paper.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
Map annotation is an important information representation method in computer-aided cartography and GIS. It is a
supplement for map symbol system. With the development of computer technology, the Automatic Placemen of
Annotation for map becomes a hotspot subject in computer-aided cartography. Usually, map Annotation is divided into
three kinds: point feature, line feature and area feature. Specifically, the Placement of Annotation in Area Feature has
being discussed by some scholars and many kinds of algorithms are given, mainly referring to the angle of the Annotation Placement. This paper discusses the Placement of Annotation in Area Feature within a point of view of the spatial geometric structure of the map, gives a new algorithm based on Map Spatial Geometry Information Measurement to complete the placement of annotation and compares the research results with the others.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
In this paper, mapping and cartography in historical geography research are topic subjects. The authors take efforts to
talk over the relationships of GIS and cartography, historical map and ancient map, historical map and contemporary
map. On the basis of historical geography studies, the compiling of Liuchao-Jiankang historical map is discussed in
details. In fact, a case study on compiling of the Distribution Density Map of Yangzhou' Registered Residences show
clearly the methods and related digital technologies on historical geography mapping.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
The paper describes an extended arc data structure, it is especially suitable in some vector-based operations. The existing
vectorial arc data structure can store and organize coordinate information effectively, but some vector-based calculations
are inefficient. Enlightened by the idea of spatial index, the paper proposed to divide arc into subsections, obtain spatial
limit information of each segment and build up to arc data structure. The paper also gives realizing method for this modified structure, analyses time efficiency and space efficiency in some frequently used procedures. Taking the computation of the distance between point and arc for example, this paper analyses the relationship between computational efficiency and sub-arc node number, gives practical results using artificial and real arcs from a GIS environment. Tests results indicated that it would improve the efficiency of vector operations, and accelerate some vector-based algorithm practical indirectly with the extended data structure.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.