Release Level	5.4
Release Date	2008 10
Revision Level	1.0

Map Import

• NEW overlays, triggered from the MapComposer tool through the button: OVERLAYS.
• EXISTING overlays to replace their current data;
• specific OBJECT geometry representation:
  1. line sources (road segments)
  2. area sources
  3. receptor areas.

For an existing overlay from the list, an alternative map/overlay data set can be imported; they must conform to the parameters defined for the current MapSet in terms of projection, coordinate system, and extent (at least partly within the overall application bounding box).
For a NEW map, map layer or overlay, the IMPORT button will trigger a dialog pop-up window where the users specifies (or select from browsing the local file system) a file name for the map data to be imported from the local client PC, browsing the local file system.

GIS formats supported

• ArcView shape files:import supported for lines and polygons one topic, one color, one line width at a time attribute table is ignored display color and line width can be selected
• Arc/Info export files: supported are single-precision, uncompressed files containing lines and/or polygons one topic, one color, one line width at a time attribute table is ignored display color and line width can be selected

• tiff: import supports pseudo and true color uncompressed and compressed images. Supported compression algorithms, are: CCITT 1D Huffman compression , CCITT Group 3 Facsimile compression , CCITT Group 4 Facsimile compression , Lempel-Ziv & Welch compression , baseline JPEG compression , word-aligned 1D Huffman compression , and PackBits compression . In addition, several nonstandard com- pression algorithms are supported: the 4-bit compression algorithm used by the ThunderScan program , NeXT 2-bit compression algorithm, an experimental LZ- style algorithm known as Deflate , and an experimental CIE LogLuv compression scheme designed for images with high dynamic range.

Import Dialog

1. To import a map data set from the Overlay Description page, the user can first select the type: vector (the default) or raster. If a reaster (TIFF) is to be imported, the origin and extent have to be defined first, else and error message will be generated. In case of a vector coverage, the origin and extent will be determined automatically from the data imported.

   For a vector coverage, the type (shapefile or e00) will be determined automatically. The user can specify in the dialog box:

   • line/border color (from an interactive color selector), default border color is BLACK;
   • line thickness in pixels;
   • Fill attributes: the default for the filling of polygons is NONE;
     • fill color (from thye the color selector)
     • fill satyle (opaque or transparent)
   To generate a filled polygon wirhout visible border, select the same color for border and opaque filling.

   The file to be imported is identified by its local (client) path and file name, or through a local interactive file browser and selection.

   A successful import is indicated by the imported data being displayed on the Overlay Description page.

   

2. To import a map data set for an area sources or receptor area boundary, a similar dialog is used. For these polygons, only vector data are applicable, and the user can specify a feature ID to extract a single feature (element) from a larger file. The display style is defined by the system to make all elements of this class appear in the same style.

Error handling

• For rasters:
  1. bounding box partially outside the MapSet bounding box (warning);
  2. bounding box completely outside the MapSet bounding box (error, abort, file rejected);
  3. pixels are not square (error, file rejected).
• For vectors:
  1. coordinates partially outside MapSet bounding box (warning);
  2. coordinates completely outside MapSet bounding box (error, abort, file rejected).
  3. wrong (not recognized) format and file structure (error, abort, file rejected);

The Map Data Import and any error encountered is also logged automatically in the System log.