Pitney Bowes MapInfo Professional - Manual (Page 79)

• Changing the Display of a Raster Image
Converting Grid Files to MapInfo Professional Grids (*.mig)
The Grid Tools (Create MapInfo Grid from Table of Objects and Create MapInfo Grid from Other Grid
Files) In MapInfo Professional allow you to convert Grid Files to MapInfo Professional Grids (*.mig).
These tools convert any grid file for which there is a grid handler present with the output being in MapInfo
Professional (*.mig) format. You can apply relief shading from a user-specifiable virtual light source and
control the color inflection values. The color files are simple text files that you can edit to specify the
color inflection values by specific value or as a percentage of the range of data values. You can open
and display the new grid after the conversion.
• For specific instructions, see Converting Grid Files to MapInfo Professional Grids and Specifying
Inflection Values with the MapInfo Professional Grid Converter in the Help System.
Adjusting the Translucency of a Grid Thematic Map
The Translucency slider control in the Modify Thematic Map dialog box allows you to control the
percentage that layers show through raster images. A translucent image allows you to partially see
through the image. Translucent images can be layered on top of other layers so that the lower layers
are partially visible through the image.
The Grid Appearance dialog box allows you to specify color inflection distribution options for
grid maps. Note:
• For specific instructions, see Adjusting the Translucency of a Grid Thematic Map in the Help System.
Working with Seamless Layers
Use or create a seamless map layer to treat a group of base tables as if they were one. A seamless
layer allows you to change display attributes, apply or change labeling or use the Layer Control window
for an entire group of tables at once. You can also retrieve information using the Info tool, and select or
browse any one of the layer's base tables. A base table can be any regular MapInfo Professional table.
Grid layers cannot be made seamless.
This feature is especially useful when you want to display a vector or raster backdrop for your maps
such as joining street or boundary maps. For example, you may have a seamless layer of county
boundaries made up of several individual county tables.
When zooming in on a seamless layer, MapInfo Professional only opens data for displaying the map at
the specific zoom level-only those component tables on display open. If you change the zoom level, then
MapInfo Professional analyzes which tiles to open and which tiles to close, and does not cache the data.
Specific raster handlers open raster images, which are usually slower than vector tables.
Features Available with Seamless Layers
Since a seamless layer is actually made up of several base tables, MapInfo Professional does treat it a
little differently than a regular MapInfo Professional table. You can use the following MapInfo Professional
features with a seamless map layer:
• Layer Control - Use any of the functions except Thematic Mapping from the Layer Control window
on your seamless layer. Add, remove, or reorder layers or set display, zoom layering or label options
for the seamless layer (all base tables) at one time. However, you cannot make a seamless layer
editable.
• Info Tool - Retrieve information about a particular object in a base table.
79 MapInfo Professional User Guide
Chapter 3: The Basics of MapInfo Professional