Table of Contents for
Web Mapping Illustrated

Version ebook / Retour

Cover image for bash Cookbook, 2nd Edition Web Mapping Illustrated by Tyler Mitchell Published by O'Reilly Media, Inc., 2005
  1. Web Mapping Illustrated
  2. Cover
  3. Web Mapping Illustrated
  4. A Note Regarding Supplemental Files
  5. Foreword
  6. Preface
  7. Youthful Exploration
  8. The Tools in This Book
  9. What This Book Covers
  10. Organization of This Book
  11. Conventions Used in This Book
  12. Safari Enabled
  13. Comments and Questions
  14. Acknowledgments
  15. 1. Introduction to Digital Mapping
  16. 1.1. The Power of Digital Maps
  17. 1.2. The Difficulties of Making Maps
  18. 1.3. Different Kinds of Web Mapping
  19. 2. Digital Mapping Tasks and Tools
  20. 2.1. Common Mapping Tasks
  21. 2.2. Common Pitfalls, Deadends, and Irritations
  22. 2.3. Identifying the Types of Tasks for a Project
  23. 3. Converting and Viewing Maps
  24. 3.1. Raster and Vector
  25. 3.2. OpenEV
  26. 3.3. MapServer
  27. 3.4. Geospatial Data Abstraction Library (GDAL)
  28. 3.5. OGR Simple Features Library
  29. 3.6. PostGIS
  30. 3.7. Summary of Applications
  31. 4. Installing MapServer
  32. 4.1. How MapServer Applications Operate
  33. 4.2. Walkthrough of the Main Components
  34. 4.3. Installing MapServer
  35. 4.4. Getting Help
  36. 5. Acquiring Map Data
  37. 5.1. Appraising Your Data Needs
  38. 5.2. Acquiring the Data You Need
  39. 6. Analyzing Map Data
  40. 6.1. Downloading the Demonstration Data
  41. 6.2. Installing Data Management Tools: GDAL and FWTools
  42. 6.3. Examining Data Content
  43. 6.4. Summarizing Information Using Other Tools
  44. 7. Converting Map Data
  45. 7.1. Converting Map Data
  46. 7.2. Converting Vector Data
  47. 7.3. Converting Raster Data to Other Formats
  48. 8. Visualizing Mapping Data in a Desktop Program
  49. 8.1. Visualization and Mapping Programs
  50. 8.2. Using OpenEV
  51. 8.3. OpenEV Basics
  52. 9. Create and Edit Personal Map Data
  53. 9.1. Planning Your Map
  54. 9.2. Preprocessing Data Examples
  55. 10. Creating Static Maps
  56. 10.1. MapServer Utilities
  57. 10.2. Sample Uses of the Command-Line Utilities
  58. 10.3. Setting Output Image Formats
  59. 11. Publishing Interactive Maps on the Web
  60. 11.1. Preparing and Testing MapServer
  61. 11.2. Create a Custom Application for a Particular Area
  62. 11.3. Continuing Education
  63. 12. Accessing Maps Through Web Services
  64. 12.1. Web Services for Mapping
  65. 12.2. What Do Web Services for Mapping Do?
  66. 12.3. Using MapServer with Web Services
  67. 12.4. Reference Map Files
  68. 13. Managing a Spatial Database
  69. 13.1. Introducing PostGIS
  70. 13.2. What Is a Spatial Database?
  71. 13.3. Downloading PostGIS Install Packages and Binaries
  72. 13.4. Compiling from Source Code
  73. 13.5. Steps for Setting Up PostGIS
  74. 13.6. Creating a Spatial Database
  75. 13.7. Load Data into the Database
  76. 13.8. Spatial Data Queries
  77. 13.9. Accessing Spatial Data from PostGIS in Other Applications
  78. 14. Custom Programming with MapServer’s MapScript
  79. 14.1. Introducing MapScript
  80. 14.2. Getting MapScript
  81. 14.3. MapScript Objects
  82. 14.4. MapScript Examples
  83. 14.5. Other Resources
  84. 14.6. Parallel MapScript Translations
  85. A. A Brief Introduction to Map Projections
  86. A.1. The Third Spheroid from the Sun
  87. A.2. Using Map Projections with MapServer
  88. A.3. Map Projection Examples
  89. A.4. Using Projections with Other Applications
  90. A.5. References
  91. B. MapServer Reference Guide for Vector Data Access
  92. B.1. Vector Data
  93. B.2. Data Format Guide
  94.  
  95. ESRI Shapefiles (SHP)
  96.  
  97. PostGIS/PostgreSQL Database
  98.  
  99. MapInfo Files (TAB/MID/MIF)
  100.  
  101. Oracle Spatial Database
  102.  
  103. Web Feature Service (WFS)
  104.  
  105. Geography Markup Language Files (GML)
  106.  
  107. VirtualSpatialData (ODBC/OVF)
  108.  
  109. TIGER/Line Files
  110.  
  111. ESRI ArcInfo Coverage Files
  112.  
  113. ESRI ArcSDE Database (SDE)
  114.  
  115. Microstation Design Files (DGN)
  116.  
  117. IHO S-57 Files
  118.  
  119. Spatial Data Transfer Standard Files (SDTS)
  120.  
  121. Inline MapServer Features
  122.  
  123. National Transfer Format Files (NTF)
  124. About the Author
  125. Colophon
  126. Copyright

Setting Output Image Formats

MapServer can produce map images, legends, and scale bars in different image formats. Throughout this chapter, the PNG format is shown in the examples because it is the default image format. MapServer packages can have different default image formats. PNG format is commonly supported by many MapServer packages, but in some cases MapServer may not be able to produce PNG files or doesn’t produce them by default.

Tip

MapServer can be compiled using many different options. The term “MapServer package” refers to the set of programs, e.g., shp2img, that you are using. The capabilities of these programs depend on how they are compiled. Some packages will have more features enabled than others.

The output image format can be explicitly set in the map file. This requires adding a single line specifying the output format you are requesting. Example 10-11 shows the additional line added to the earlier example map file.

Example 10-11. Specifying the output image format as JPEG
MAP
  SIZE 600 300
  EXTENT -180 -90 180 90
  IMAGECOLOR 180 180 250
  IMAGETYPE JPEG

  UNITS DD
...

This setting can be overridden when using the shp2img command with the -i option. It can’t be overridden when using commands such as scalebar or legend, as mentioned earlier in “Creating Your First Map Image.”

The IMAGETYPE specified must be one supported by the MapServer package you are running. To check what output formats your installation supports, run the mapserv file (or mapserv.exe on Windows) with the -v option. This option tells you what input and output formats are supported by the utilities in your MapServer package. The following example shows the output from the MapServer used in this chapter, with the output image formats highlighted:

            
    > mapserv -v
    MapServer version 4.4.1 OUTPUT=PNG OUTPUT=JPEG OUTPUT=WBMP
             SUPPORTS=PROJ
    SUPPORTS=FREETYPE SUPPORTS=WMS_SERVER SUPPORTS=WMS_CLIENT SUPPORTS=WFS_SERVER
    SUPPORTS=WFS_CLIENT INPUT=EPPL7 INPUT=POSTGIS INPUT=OGR INPUT=GDAL INPUT=SHAPEFILE

This listing shows that this installation of MapServer can only output PNG, JPEG, or WBMP format files. That means the IMAGETYPE could be set to either of those three. Therefore it can’t output GIF, TIFF, PDF, or any other formats.

Warning

WBMP images produced by MapServer appear to be unreadable. This may only be a problem for non-Windows environments.

For many vector-mapping applications, the PNG output format is sufficient. In many cases it will be the default output format. If you have a raster layer with more than 256 colors, it will probably not look right using the default PNG image type. Usually, all that is needed is to increase the depth of colors that MapServer creates in the output image. This can be set by requesting a 24-bit version of the PNG output format such as:

    IMAGETYPE PNG24

Be warned: increasing the color depth also increases the file size of your images. This can be a major performance issue when sending graphics across the web.

More specific output image format settings can be made using an OUTPUTFORMAT object in your map file. This is an advanced topic and isn’t described here. Please refer to the MapServer documentation at http://mapserver.gis.umn.edu/doc/mapfile-reference.html#outputformat.