Autodesk 15606-011408-9008 - MAPGUIDE R6.3 NAMED-100U PK, Руководство пользователя

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Working with Raster Images
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Raster Image Catalog Files
In addition to individual raster image files, Autodesk MapGuide supports
Raster Image Catalog (RIC) files. A RIC is a list of raster image files and their
lower-left and upper-right coordinates. When creating a raster map layer, you
can reference an individual raster image in any of the supported formats
shown on page 101, or in a RIC file. Each raster image file (whether an indi-
vidual image or a RIC) must be accompanied by a georeferencing file, which
provides additional information about how to position the raster image on
the map. Note that GeoTIFF files do not require a separate georeferencing file.
Raster images in ECW and MrSID format are already optimized, so there is no
reason to include them in RIC files.
When you access a layer that references a RIC file, Autodesk MapGuide Server
scans through the RIC file to determine the images or portions of images that
correspond to the area being viewed, and then sends only the data for that
area. This greatly increases performance, as only the necessary data is stored
in memory instead of the entire image.
It is important to keep in mind that the RIC file only determines which
images might be visible. Georeferencing information for each individual
raster image must still be available, as this information—not the information
in the RIC file—is used to place them in the correct position on the map.
Note that the raster image must be based on the same coordinate system as
the rest of the data on the map, and it cannot be converted automatically if
you change the coordinate system for the map.
If Autodesk MapGuide Server is running under the System account, please
note the following:
All of the image files in the RIC must be on the same server as the RIC.
The RIC must reference the raster image files using relative paths. If you
use a computer name in the path, Windows NT/2000 will not be able to
recognize it.
Raster Image Catalog File Format
Raster image catalog files are ASCII, comma-delimited (CSV) files with the
following format:
"<Name of the raster image file1>",<xMin>,<yMin>,<xMax>,<yMax>
"<Name of the raster image file2>",<xMin>,<yMin>,<xMax>,<yMax>
"<Name of the raster image file3>",<xMin>,<yMin>,<xMax>,<yMax>
...
"<Name of the raster image file
n >",<xMin>,<yMin>,<xMax>,<yMax>